v0.0.25 - Add --allow-all flag and short aliases for CLI options

.roo/commands/push.md

@@ -1,5 +1,5 @@
 ---
-description: "Brief description of what this command does"
+description: "This command increments the version number and then adds, commits and pushes to the repo."
 ---
 
 Run increment_and_push.sh, and supply a good git commit message. For example:

Dockerfile.alpine-musl

@@ -80,6 +80,7 @@ RUN ARCH="$(uname -m)"; \
       /build/src/transport_frame.c \
       /build/src/key_store.c \
       /build/src/socket_name.c \
+      /build/src/auth_envelope.c \
       "$NOSTR_LIB" \
       -o /build/nsigner_static \
       $(pkg-config --static --libs libcurl openssl) \

Makefile

@@ -5,6 +5,8 @@ LDFLAGS := -Wl,--gc-sections resources/nostr_core_lib/libnostr_core_x64.a -lz -l
 SRC_DIR := src
 BUILD_DIR := build
 TEST_DIR := tests
+CLIENT_DIR := client
+EXAMPLES_DIR := examples
 
 TARGET_DEV := $(BUILD_DIR)/nsigner
 
@@ -20,7 +22,8 @@ SOURCES := \
 	$(SRC_DIR)/server.c \
 	$(SRC_DIR)/transport_frame.c \
 	$(SRC_DIR)/key_store.c \
-	$(SRC_DIR)/socket_name.c
+	$(SRC_DIR)/socket_name.c \
+	$(SRC_DIR)/auth_envelope.c
 
 HEADERS :=
 
@@ -33,8 +36,12 @@ TEST_DISPATCHER_TARGET := $(BUILD_DIR)/test_dispatcher
 TEST_POLICY_TARGET := $(BUILD_DIR)/test_policy
 TEST_INTEGRATION_TARGET := $(BUILD_DIR)/test_integration
 TEST_SOCKET_NAME_TARGET := $(BUILD_DIR)/test_socket_name
+TEST_AUTH_ENVELOPE_TARGET := $(BUILD_DIR)/test_auth_envelope
+TEST_QREXEC_AUTH_TARGET := $(BUILD_DIR)/test_qrexec_auth
+EXAMPLE_GET_PUBLIC_KEY_TARGET := $(BUILD_DIR)/example_get_public_key_client
+EXAMPLE_SIGN_EVENT_TARGET := $(BUILD_DIR)/example_sign_event_client
 
-.PHONY: all lib dev static static-debug static-arm64 test test-integration test-mnemonic test-role test-selector test-enforcement test-dispatcher test-policy test-socket-name clean
+.PHONY: all lib dev static static-debug static-arm64 test test-integration test-mnemonic test-role test-selector test-enforcement test-dispatcher test-policy test-socket-name test-auth-envelope test-qrexec-auth examples test-client clean
 
 all: dev
 
@@ -59,7 +66,7 @@ static-arm64:
 	chmod +x ./build_static.sh
 	./build_static.sh --arch arm64
 
-test: lib test-mnemonic test-role test-selector test-enforcement test-dispatcher test-policy test-socket-name
+test: lib test-mnemonic test-role test-selector test-enforcement test-dispatcher test-policy test-socket-name test-auth-envelope test-qrexec-auth test-client
 
 test-integration: $(TEST_INTEGRATION_TARGET) $(TARGET_DEV)
 	./$(TEST_INTEGRATION_TARGET)
@@ -85,6 +92,16 @@ test-policy: $(TEST_POLICY_TARGET)
 test-socket-name: $(TEST_SOCKET_NAME_TARGET)
 	./$(TEST_SOCKET_NAME_TARGET)
 
+test-auth-envelope: $(TEST_AUTH_ENVELOPE_TARGET)
+	./$(TEST_AUTH_ENVELOPE_TARGET)
+
+test-qrexec-auth: $(TEST_QREXEC_AUTH_TARGET) $(TARGET_DEV)
+	./$(TEST_QREXEC_AUTH_TARGET)
+
+test-client: examples
+
+examples: $(EXAMPLE_GET_PUBLIC_KEY_TARGET) $(EXAMPLE_SIGN_EVENT_TARGET)
+
 $(TEST_MNEMONIC_TARGET): $(TEST_DIR)/test_mnemonic.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c
 	@mkdir -p $(BUILD_DIR)
 	$(CC) $(CFLAGS) $(TEST_DIR)/test_mnemonic.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c -o $(TEST_MNEMONIC_TARGET) $(LDFLAGS)
@@ -109,13 +126,29 @@ $(TEST_POLICY_TARGET): $(TEST_DIR)/test_policy.c $(SRC_DIR)/policy.c
 	@mkdir -p $(BUILD_DIR)
 	$(CC) $(CFLAGS) $(TEST_DIR)/test_policy.c $(SRC_DIR)/policy.c -o $(TEST_POLICY_TARGET) $(LDFLAGS)
 
-$(TEST_INTEGRATION_TARGET): $(TEST_DIR)/test_integration.c
+$(TEST_INTEGRATION_TARGET): $(TEST_DIR)/test_integration.c $(CLIENT_DIR)/nsigner_client.c $(SRC_DIR)/auth_envelope.c
 	@mkdir -p $(BUILD_DIR)
-	$(CC) $(CFLAGS) $(TEST_DIR)/test_integration.c -o $(TEST_INTEGRATION_TARGET) $(LDFLAGS)
+	$(CC) $(CFLAGS) -I$(CLIENT_DIR) $(TEST_DIR)/test_integration.c $(CLIENT_DIR)/nsigner_client.c $(SRC_DIR)/auth_envelope.c -o $(TEST_INTEGRATION_TARGET) $(LDFLAGS)
 
 $(TEST_SOCKET_NAME_TARGET): $(TEST_DIR)/test_socket_name.c $(SRC_DIR)/socket_name.c
 	@mkdir -p $(BUILD_DIR)
 	$(CC) $(CFLAGS) $(TEST_DIR)/test_socket_name.c $(SRC_DIR)/socket_name.c -o $(TEST_SOCKET_NAME_TARGET) $(LDFLAGS)
 
+$(TEST_AUTH_ENVELOPE_TARGET): $(TEST_DIR)/test_auth_envelope.c $(SRC_DIR)/auth_envelope.c
+	@mkdir -p $(BUILD_DIR)
+	$(CC) $(CFLAGS) $(TEST_DIR)/test_auth_envelope.c $(SRC_DIR)/auth_envelope.c -o $(TEST_AUTH_ENVELOPE_TARGET) $(LDFLAGS)
+
+$(TEST_QREXEC_AUTH_TARGET): $(TEST_DIR)/test_qrexec_auth.c $(SRC_DIR)/auth_envelope.c
+	@mkdir -p $(BUILD_DIR)
+	$(CC) $(CFLAGS) $(TEST_DIR)/test_qrexec_auth.c $(SRC_DIR)/auth_envelope.c -o $(TEST_QREXEC_AUTH_TARGET) $(LDFLAGS)
+
+$(EXAMPLE_GET_PUBLIC_KEY_TARGET): $(EXAMPLES_DIR)/get_public_key_client.c $(CLIENT_DIR)/nsigner_client.c $(SRC_DIR)/auth_envelope.c
+	@mkdir -p $(BUILD_DIR)
+	$(CC) $(CFLAGS) -I$(CLIENT_DIR) $(EXAMPLES_DIR)/get_public_key_client.c $(CLIENT_DIR)/nsigner_client.c $(SRC_DIR)/auth_envelope.c -o $(EXAMPLE_GET_PUBLIC_KEY_TARGET) $(LDFLAGS)
+
+$(EXAMPLE_SIGN_EVENT_TARGET): $(EXAMPLES_DIR)/sign_event_client.c $(CLIENT_DIR)/nsigner_client.c $(SRC_DIR)/auth_envelope.c
+	@mkdir -p $(BUILD_DIR)
+	$(CC) $(CFLAGS) -I$(CLIENT_DIR) $(EXAMPLES_DIR)/sign_event_client.c $(CLIENT_DIR)/nsigner_client.c $(SRC_DIR)/auth_envelope.c -o $(EXAMPLE_SIGN_EVENT_TARGET) $(LDFLAGS)
+
 clean:
 	rm -rf $(BUILD_DIR)

client/README.md

@@ -0,0 +1,47 @@
+# n_signer C Reference Client
+
+This directory provides a minimal copy/paste-friendly C client for `n_signer`.
+
+## Files
+
+- `nsigner_client.h` / `nsigner_client.c`:
+  - Unix abstract socket connect helper
+  - length-prefixed frame send/receive
+  - generic request API
+  - helpers for `get_public_key` and `sign_event`
+  - optional TCP auth envelope attachment via `auth_envelope_build_for_request()`
+
+## API at a glance
+
+```c
+nsigner_client_t client;
+nsigner_client_init(&client);
+
+nsigner_client_connect_unix(&client, "nsigner", 5000);
+
+char *resp = NULL;
+nsigner_client_get_public_key(&client, "1", "", &resp);
+free(resp);
+
+nsigner_client_close(&client);
+```
+
+## Auth envelope usage
+
+If transport requires auth envelopes (for TCP mode), set a private key once:
+
+```c
+unsigned char privkey[32] = { /* caller key */ };
+nsigner_client_set_auth(&client, privkey, "example-client");
+```
+
+Subsequent requests automatically include an `auth` object.
+
+## Ownership rules
+
+- Any `out_response_json` returned by the API must be freed by caller using `free()`.
+- `nsigner_client_close()` only closes the socket; it does not free the client struct itself.
+
+## License
+
+Source files in this directory use SPDX `0BSD` headers for permissive reuse in external projects.

client/nsigner_client.c

@@ -0,0 +1,369 @@
+/*
+ * SPDX-License-Identifier: 0BSD
+ */
+
+#define _GNU_SOURCE
+
+#include "nsigner_client.h"
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <cJSON.h>
+
+#include "auth_envelope.h"
+
+#define NSIGNER_CLIENT_MAX_FRAME (65536U)
+
+static void client_set_error(nsigner_client_t *client, const char *fmt, ...) {
+    va_list ap;
+
+    if (client == NULL) {
+        return;
+    }
+
+    va_start(ap, fmt);
+    vsnprintf(client->last_error, sizeof(client->last_error), fmt, ap);
+    va_end(ap);
+}
+
+static int write_full(int fd, const void *buf, size_t len) {
+    const unsigned char *p = (const unsigned char *)buf;
+    size_t off = 0;
+
+    while (off < len) {
+        ssize_t n = write(fd, p + off, len - off);
+        if (n < 0) {
+            if (errno == EINTR) {
+                continue;
+            }
+            return -1;
+        }
+        off += (size_t)n;
+    }
+
+    return 0;
+}
+
+static int read_full(int fd, void *buf, size_t len) {
+    unsigned char *p = (unsigned char *)buf;
+    size_t off = 0;
+
+    while (off < len) {
+        ssize_t n = read(fd, p + off, len - off);
+        if (n == 0) {
+            return -1;
+        }
+        if (n < 0) {
+            if (errno == EINTR) {
+                continue;
+            }
+            return -1;
+        }
+        off += (size_t)n;
+    }
+
+    return 0;
+}
+
+static int send_framed(int fd, const char *payload) {
+    uint32_t len;
+    uint32_t be_len;
+
+    if (payload == NULL) {
+        return -1;
+    }
+
+    len = (uint32_t)strlen(payload);
+    be_len = htonl(len);
+
+    if (write_full(fd, &be_len, sizeof(be_len)) != 0) {
+        return -1;
+    }
+    if (write_full(fd, payload, len) != 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
+static int recv_framed(int fd, char **out_payload) {
+    uint32_t be_len;
+    uint32_t len;
+    char *payload;
+
+    if (out_payload == NULL) {
+        return -1;
+    }
+
+    *out_payload = NULL;
+
+    if (read_full(fd, &be_len, sizeof(be_len)) != 0) {
+        return -1;
+    }
+
+    len = ntohl(be_len);
+    if (len == 0 || len > NSIGNER_CLIENT_MAX_FRAME) {
+        return -1;
+    }
+
+    payload = (char *)malloc((size_t)len + 1U);
+    if (payload == NULL) {
+        return -1;
+    }
+
+    if (read_full(fd, payload, len) != 0) {
+        free(payload);
+        return -1;
+    }
+
+    payload[len] = '\0';
+    *out_payload = payload;
+    return 0;
+}
+
+static int sleep_ms(int ms) {
+    struct timespec ts;
+    ts.tv_sec = ms / 1000;
+    ts.tv_nsec = (long)(ms % 1000) * 1000000L;
+    return nanosleep(&ts, NULL);
+}
+
+void nsigner_client_init(nsigner_client_t *client) {
+    if (client == NULL) {
+        return;
+    }
+
+    memset(client, 0, sizeof(*client));
+    client->fd = -1;
+    client->timeout_ms = 5000;
+}
+
+void nsigner_client_close(nsigner_client_t *client) {
+    if (client == NULL) {
+        return;
+    }
+
+    if (client->fd >= 0) {
+        close(client->fd);
+        client->fd = -1;
+    }
+}
+
+int nsigner_client_connect_unix(nsigner_client_t *client,
+                                const char *socket_name,
+                                int timeout_ms) {
+    struct sockaddr_un addr;
+    socklen_t addr_len;
+    int elapsed = 0;
+
+    if (client == NULL || socket_name == NULL || socket_name[0] == '\0') {
+        return -1;
+    }
+
+    timeout_ms = (timeout_ms > 0) ? timeout_ms : 5000;
+    nsigner_client_close(client);
+
+    memset(&addr, 0, sizeof(addr));
+    addr.sun_family = AF_UNIX;
+    addr.sun_path[0] = '\0';
+    strncpy(&addr.sun_path[1], socket_name, sizeof(addr.sun_path) - 2);
+    addr.sun_path[sizeof(addr.sun_path) - 1] = '\0';
+    addr_len = (socklen_t)(sizeof(sa_family_t) + 1 + strlen(socket_name));
+
+    while (elapsed < timeout_ms) {
+        int fd = socket(AF_UNIX, SOCK_STREAM, 0);
+        if (fd < 0) {
+            client_set_error(client, "socket failed: %s", strerror(errno));
+            return -1;
+        }
+
+        if (connect(fd, (struct sockaddr *)&addr, addr_len) == 0) {
+            client->fd = fd;
+            client->timeout_ms = timeout_ms;
+            client_set_error(client, "ok");
+            return 0;
+        }
+
+        close(fd);
+        sleep_ms(100);
+        elapsed += 100;
+    }
+
+    client_set_error(client, "connect timeout: %s", strerror(errno));
+    return -1;
+}
+
+int nsigner_client_set_auth(nsigner_client_t *client,
+                            const unsigned char privkey[32],
+                            const char *label) {
+    if (client == NULL || privkey == NULL) {
+        return -1;
+    }
+
+    memcpy(client->auth_privkey, privkey, 32);
+    client->auth_enabled = 1;
+
+    if (label == NULL) {
+        label = "";
+    }
+    strncpy(client->auth_label, label, sizeof(client->auth_label) - 1);
+    client->auth_label[sizeof(client->auth_label) - 1] = '\0';
+
+    return 0;
+}
+
+const char *nsigner_client_last_error(const nsigner_client_t *client) {
+    if (client == NULL) {
+        return "invalid_client";
+    }
+    return client->last_error;
+}
+
+int nsigner_client_request_raw(nsigner_client_t *client,
+                               const char *request_json,
+                               char **out_response_json) {
+    char *response_json = NULL;
+
+    if (client == NULL || request_json == NULL || out_response_json == NULL) {
+        return -1;
+    }
+    if (client->fd < 0) {
+        client_set_error(client, "not connected");
+        return -1;
+    }
+
+    *out_response_json = NULL;
+
+    if (send_framed(client->fd, request_json) != 0) {
+        client_set_error(client, "send failed");
+        return -1;
+    }
+
+    if (recv_framed(client->fd, &response_json) != 0) {
+        client_set_error(client, "receive failed");
+        return -1;
+    }
+
+    *out_response_json = response_json;
+    client_set_error(client, "ok");
+    return 0;
+}
+
+int nsigner_client_request(nsigner_client_t *client,
+                           const char *id,
+                           const char *method,
+                           const cJSON *params,
+                           char **out_response_json) {
+    cJSON *root = NULL;
+    cJSON *params_copy = NULL;
+    cJSON *auth = NULL;
+    char *request_json = NULL;
+    int rc = -1;
+
+    if (client == NULL || id == NULL || method == NULL || out_response_json == NULL) {
+        return -1;
+    }
+
+    root = cJSON_CreateObject();
+    if (root == NULL) {
+        client_set_error(client, "out of memory");
+        goto cleanup;
+    }
+
+    cJSON_AddStringToObject(root, "id", id);
+    cJSON_AddStringToObject(root, "method", method);
+
+    if (params != NULL) {
+        params_copy = cJSON_Duplicate((cJSON *)params, 1);
+    } else {
+        params_copy = cJSON_CreateArray();
+    }
+
+    if (params_copy == NULL) {
+        client_set_error(client, "failed to create params");
+        goto cleanup;
+    }
+    cJSON_AddItemToObject(root, "params", params_copy);
+
+    if (client->auth_enabled) {
+        if (auth_envelope_build_for_request(id,
+                                            method,
+                                            params_copy,
+                                            client->auth_privkey,
+                                            client->auth_label,
+                                            time(NULL),
+                                            &auth) != 0) {
+            client_set_error(client, "failed to build auth envelope");
+            goto cleanup;
+        }
+        cJSON_AddItemToObject(root, "auth", auth);
+        auth = NULL;
+    }
+
+    request_json = cJSON_PrintUnformatted(root);
+    if (request_json == NULL) {
+        client_set_error(client, "failed to serialize request");
+        goto cleanup;
+    }
+
+    rc = nsigner_client_request_raw(client, request_json, out_response_json);
+
+cleanup:
+    cJSON_Delete(root);
+    cJSON_Delete(auth);
+    free(request_json);
+    return rc;
+}
+
+int nsigner_client_get_public_key(nsigner_client_t *client,
+                                  const char *id,
+                                  const char *selector,
+                                  char **out_response_json) {
+    cJSON *params = cJSON_CreateArray();
+    int rc;
+
+    if (params == NULL) {
+        return -1;
+    }
+
+    cJSON_AddItemToArray(params, cJSON_CreateString((selector != NULL) ? selector : ""));
+    rc = nsigner_client_request(client, id, "get_public_key", params, out_response_json);
+    cJSON_Delete(params);
+    return rc;
+}
+
+int nsigner_client_sign_event(nsigner_client_t *client,
+                              const char *id,
+                              const char *event_json,
+                              const char *role,
+                              char **out_response_json) {
+    cJSON *params = cJSON_CreateArray();
+    cJSON *opts = cJSON_CreateObject();
+    int rc;
+
+    if (params == NULL || opts == NULL || event_json == NULL) {
+        cJSON_Delete(params);
+        cJSON_Delete(opts);
+        return -1;
+    }
+
+    cJSON_AddItemToArray(params, cJSON_CreateString(event_json));
+    if (role != NULL && role[0] != '\0') {
+        cJSON_AddStringToObject(opts, "role", role);
+    }
+    cJSON_AddItemToArray(params, opts);
+
+    rc = nsigner_client_request(client, id, "sign_event", params, out_response_json);
+    cJSON_Delete(params);
+    return rc;
+}

client/nsigner_client.h

@@ -0,0 +1,56 @@
+/*
+ * SPDX-License-Identifier: 0BSD
+ */
+
+#ifndef NSIGNER_CLIENT_H
+#define NSIGNER_CLIENT_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <cJSON.h>
+
+typedef struct {
+    int fd;
+    int timeout_ms;
+    unsigned char auth_privkey[32];
+    int auth_enabled;
+    char auth_label[64];
+    char last_error[128];
+} nsigner_client_t;
+
+void nsigner_client_init(nsigner_client_t *client);
+void nsigner_client_close(nsigner_client_t *client);
+
+int nsigner_client_connect_unix(nsigner_client_t *client,
+                                const char *socket_name,
+                                int timeout_ms);
+
+int nsigner_client_set_auth(nsigner_client_t *client,
+                            const unsigned char privkey[32],
+                            const char *label);
+
+const char *nsigner_client_last_error(const nsigner_client_t *client);
+
+int nsigner_client_request_raw(nsigner_client_t *client,
+                               const char *request_json,
+                               char **out_response_json);
+
+int nsigner_client_request(nsigner_client_t *client,
+                           const char *id,
+                           const char *method,
+                           const cJSON *params,
+                           char **out_response_json);
+
+int nsigner_client_get_public_key(nsigner_client_t *client,
+                                  const char *id,
+                                  const char *selector,
+                                  char **out_response_json);
+
+int nsigner_client_sign_event(nsigner_client_t *client,
+                              const char *id,
+                              const char *event_json,
+                              const char *role,
+                              char **out_response_json);
+
+#endif

documents/CLIENT_IMPLEMENTATION.md

@@ -6,14 +6,21 @@ This document is the client-integration spec for `nsigner`.
 
 It is written for agent/tool authors implementing robust request flows against the local signer process.
 
+Reference implementation in this repository:
+
+- Reusable C client library: `client/nsigner_client.h` + `client/nsigner_client.c`
+- Minimal usage examples: `examples/get_public_key_client.c` and `examples/sign_event_client.c`
+- Auth envelope builder used by the client: `src/auth_envelope.h` (`auth_envelope_build_for_request`)
+
 ---
 
 ## 2. Discovery and socket targeting
 
-`nsigner` currently supports two transport families:
+`nsigner` currently supports three transport families:
 
 - Linux AF_UNIX **abstract namespace** sockets.
 - Stdio framed mode (`--listen stdio` and `--listen qrexec`) for one request/response exchange.
+- TCP framed mode (`--listen tcp:IPv4:PORT` or `--listen tcp:[IPv6]:PORT`).
 
 For AF_UNIX:
 
@@ -54,6 +61,24 @@ In server mode:
 
 This mode is server-side only in the current CLI (the `client` subcommand still targets AF_UNIX).
 
+### 2.4 qrexec authentication posture (`--auth`)
+
+qrexec now supports configurable auth-envelope handling:
+
+- `--listen qrexec --auth off` (default): legacy behavior. Requests are authorized as `qubes:<vm-name>` only.
+- `--listen qrexec --auth optional`: if the request includes an `auth` field, it is verified using the same auth envelope rules as TCP. On success, caller identity is upgraded to `qubes:<vm-name>+pubkey:<hex>`.
+- `--listen qrexec --auth required`: every request must carry a valid `auth` envelope, and caller identity is `qubes:<vm-name>+pubkey:<hex>`.
+
+When `--auth optional` is used, a malformed or invalid `auth` object is rejected with auth-layer errors (`2010..2017`) rather than silently falling back to `qubes:<vm-name>`.
+
+### 2.5 TCP mode authentication (required)
+
+For TCP transport, requests MUST include an `auth` object containing a signed Nostr-style event envelope.
+
+- Missing `auth` returns `{"error":{"code":2014,"message":"auth_envelope_required"}}`.
+- Signature verification, method/id/body binding, timestamp skew checks, and replay checks are enforced before policy lookup.
+- On success, caller identity is normalized to `pubkey:<hex>` for policy checks.
+
 ---
 
 ## 3. Transport framing
@@ -147,6 +172,14 @@ Representative error names clients must handle:
 - `unauthorized`
 - `approval_denied`
 - `internal_error`
+- `auth_envelope_malformed` (2010)
+- `auth_body_mismatch` (2011)
+- `auth_signature_invalid` (2012)
+- `auth_kind_invalid` (2013)
+- `auth_envelope_required` (2014)
+- `auth_envelope_mismatch` (2015)
+- `auth_envelope_stale` (2016)
+- `auth_replay_detected` (2017)
 
 ### 5.1 Recovery guidance
 
@@ -158,6 +191,7 @@ Representative error names clients must handle:
 - `unauthorized`: caller identity disallowed by policy; do not blind-retry.
 - `approval_denied`: user rejected prompt; treat as final unless user initiates retry.
 - `internal_error`: bounded retry with backoff; surface diagnostics.
+- `auth_envelope_*` / `auth_*` (2010-2017): fix request signing/auth envelope generation; do not blind-retry unchanged payloads.
 
 ---
 

documents/N_OS_TR_AGENT_CHANGES.md

@@ -0,0 +1,56 @@
+# n_OS_tr Agent Guide: Handling n_signer v0.0.16 Changes
+
+This is a short operational guide for the n_OS_tr agent after the approval-model update in `n_signer`.
+
+## What changed
+
+- `n_signer` is now **deny-by-default**.
+- First-time caller/index combinations require approval unless preapproved.
+- `nostr_index` values can be auto-derived on approval.
+- Policy decisions are visible in activity labels: `:preapprove`, `:session-grant`, `:prompt`, `:no-match`.
+
+## What the agent should do
+
+1. **Always send explicit selector options** in the last `params` item:
+   - Prefer `{"nostr_index": N}` for service identities.
+2. **Expect `policy_denied` on first contact** if caller/index is not preapproved.
+3. **Do not retry blindly** on `policy_denied`.
+   - Surface a clear status: "approval needed".
+4. **Treat `unknown_role` as actionable**:
+   - If using `nostr_index`, request again only after human approval or valid preapprove config.
+5. **Use stable caller identity** (service name / VM identity) so preapprove rules match reliably.
+
+## Required startup pattern for n_OS_tr services
+
+Launch `n_signer` with explicit `--preapprove` entries for each boot service that must sign without prompts.
+
+Example:
+
+```ini
+ExecStart=/usr/bin/n_signer \
+  --preapprove caller=qubes:nostr-relay,role=main \
+  --preapprove caller=qubes:dm-handler,nostr_index=1 \
+  --preapprove caller=qubes:contacts,nostr_index=2 \
+  --preapprove caller=qubes:zaps,nostr_index=3
+```
+
+## Agent error-handling policy (recommended)
+
+- `policy_denied` → stop, mark as "awaiting approval/preapprove".
+- `unknown_role` with `nostr_index` → stop, mark as "identity not yet approved/created".
+- `purpose_mismatch` / `curve_mismatch` → configuration bug; fail hard and alert.
+- `ambiguous_role_selector` → client bug; send exactly one selector field.
+
+## Observability checks
+
+When troubleshooting, inspect n_signer activity lines:
+
+- `ALLOWED:preapprove` → expected for boot services.
+- `ALLOWED:session-grant` → interactive approval happened earlier this session.
+- `ALLOWED:prompt` → just approved now.
+- `DENIED:no-match` → no policy entry matched caller/index.
+
+## Operational rule of thumb
+
+For n_OS_tr system services, rely on `--preapprove` at startup.
+For ad-hoc/manual clients, rely on interactive prompt approvals.

documents/QUBES_OS.md

@@ -49,6 +49,16 @@ Still missing for complete Qubes integration:
 - qrexec policy in dom0 remains first enforcement boundary.
 - `n_signer` policy/approval remains second boundary.
 
+### 3.4 Optional per-program identity inside one qube (`--auth optional`)
+
+qrexec now supports an optional auth-envelope layer:
+
+- `nsigner --listen qrexec --auth off` (default): identity remains `qubes:<source-vm>`.
+- `nsigner --listen qrexec --auth optional`: if a caller includes a valid auth envelope, identity becomes `qubes:<source-vm>+pubkey:<hex>`.
+- `nsigner --listen qrexec --auth required`: all requests must carry valid envelopes and identity is always `qubes:<source-vm>+pubkey:<hex>`.
+
+This enables per-program approvals inside a single caller qube while preserving existing behavior for legacy callers that do not emit auth envelopes.
+
 ---
 
 ## 4. Required implementation tasks
@@ -102,6 +112,12 @@ In qrexec mode, default prompt behavior is now:
 
 This replaces the previous permissive `PROMPT_NEVER` temporary setting.
 
+If qrexec auth envelopes are enabled (`--auth optional` or `--auth required`), approved callers can also be recorded as composite identities:
+
+- `qubes:<vm>+pubkey:<hex>`
+
+This gives independent approval rows for distinct programs running in the same source qube.
+
 ## 4.4 Client helper examples ✅ Implemented
 
 Added:
@@ -135,6 +151,7 @@ Includes:
 - from caller qube, invoke test request (`get_public_key`)
 - confirm signer qube receives request
 - confirm activity log displays `qubes:<source-vm>` caller prefix
+- with `--auth optional`, confirm envelope-enabled clients show `qubes:<source-vm>+pubkey:<hex>`
 - validate deny behavior from unauthorized qube
 
 ## 5.4 Failure checks

documents/SECURITY.md

@@ -94,12 +94,13 @@ An identity is a tagged caller record built from the transport. Different transp
 |---|---|---|
 | `unix_peer` | `uid`, `pid` from `SO_PEERCRED` on an abstract Unix socket. | Kernel — the client cannot forge it. |
 | `qubes` | source qube name from `QREXEC_REMOTE_DOMAIN`. | Qubes RPC framework. |
+| `qubes_pubkey` | source qube + verified auth-envelope pubkey (`qubes:<vm>+pubkey:<hex>`). | Qubes RPC framework + application-layer signature verification. |
 | `tcp_local` | Loopback address of caller. | TCP socket peer address — opt-in transport. |
-| `tcp_remote` | Address plus an authenticated pubkey (planned). | Application-layer authentication. |
+| `tcp_remote` | Verified auth-envelope pubkey (`pubkey:<hex>`). | Application-layer authentication. |
 | `fips` | Peer npub from a NIP-46 style flow (planned). | Application-layer authentication. |
 | `usb_serial` | Device path plus an asserted caller (planned). | Trust-on-first-use. |
 
-Identity quality varies. `unix_peer` and `qubes` are vouched for by the kernel or hypervisor — strong. `tcp_local` and `tcp_remote` are transport-asserted only — only as good as the human at the terminal who chose to approve them.
+Identity quality varies. `unix_peer` and `qubes` are vouched for by the kernel or hypervisor — strong. `qubes_pubkey` is stronger still for multi-program qubes because it combines hypervisor-vouched source-qube identity with a per-program cryptographic identity. `tcp_local` and `tcp_remote` rely on transport/app-layer checks and are only as strong as deployment choices.
 
 ### Index (or path) — *which key*
 
@@ -423,14 +424,16 @@ Different transports give different identity quality. The wire format (4-byte le
 ### 11.2 Stdio / qrexec mode
 
 - One framed request, one framed response, then exit.
-- Identity: `qubes:<vm-name>` from `QREXEC_REMOTE_DOMAIN`, vouched for by Qubes.
+- Identity defaults to `qubes:<vm-name>` from `QREXEC_REMOTE_DOMAIN`, vouched for by Qubes.
+- With `--listen qrexec --auth optional|required`, requests carrying a valid auth envelope are upgraded to `qubes:<vm-name>+pubkey:<hex>`.
 - Risk surface: only what Qubes RPC policy permits. See [`packaging/qubes/`](../packaging/qubes/).
 
 ### 11.3 TCP (advanced / opt-in)
 
-- Loopback addresses produce `tcp_local` identities. Remote addresses produce `tcp_remote` identities.
-- Identity is **transport-asserted only**. The TCP peer address proves a route, not a principal.
-- For TCP transports the **interactive approval prompt is the real authentication mechanism**. Do not enable TCP transports without a trustworthy local terminal.
+- Loopback and remote TCP callers must present a valid signed auth envelope.
+- Identity is normalized to caller `pubkey:<hex>` after signature verification; TCP peer address is context only.
+- The auth gate runs before policy: missing/invalid envelopes are rejected with `2010..2017` auth errors.
+- Prompt-driven approval still applies after auth; auth answers "who is calling", policy answers "is this caller allowed".
 
 ### 11.4 Future transports
 

examples/get_public_key_client.c

@@ -0,0 +1,32 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "../client/nsigner_client.h"
+
+int main(int argc, char **argv) {
+    const char *socket_name = "nsigner";
+    nsigner_client_t client;
+    char *response = NULL;
+
+    if (argc > 1 && argv[1] != NULL && argv[1][0] != '\0') {
+        socket_name = argv[1];
+    }
+
+    nsigner_client_init(&client);
+
+    if (nsigner_client_connect_unix(&client, socket_name, 5000) != 0) {
+        fprintf(stderr, "connect failed: %s\n", nsigner_client_last_error(&client));
+        return 1;
+    }
+
+    if (nsigner_client_get_public_key(&client, "example-1", "", &response) != 0) {
+        fprintf(stderr, "request failed: %s\n", nsigner_client_last_error(&client));
+        nsigner_client_close(&client);
+        return 1;
+    }
+
+    printf("%s\n", response);
+    free(response);
+    nsigner_client_close(&client);
+    return 0;
+}

examples/sign_event_client.c

@@ -0,0 +1,33 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "../client/nsigner_client.h"
+
+int main(int argc, char **argv) {
+    const char *socket_name = "nsigner";
+    const char *event_json = "{\"kind\":1,\"content\":\"hello from client example\",\"tags\":[],\"created_at\":1700000000}";
+    nsigner_client_t client;
+    char *response = NULL;
+
+    if (argc > 1 && argv[1] != NULL && argv[1][0] != '\0') {
+        socket_name = argv[1];
+    }
+
+    nsigner_client_init(&client);
+
+    if (nsigner_client_connect_unix(&client, socket_name, 5000) != 0) {
+        fprintf(stderr, "connect failed: %s\n", nsigner_client_last_error(&client));
+        return 1;
+    }
+
+    if (nsigner_client_sign_event(&client, "example-2", event_json, "main", &response) != 0) {
+        fprintf(stderr, "request failed: %s\n", nsigner_client_last_error(&client));
+        nsigner_client_close(&client);
+        return 1;
+    }
+
+    printf("%s\n", response);
+    free(response);
+    nsigner_client_close(&client);
+    return 0;
+}

increment_and_push.sh

@@ -153,14 +153,42 @@ git_commit_and_push_no_tag() {
     git push origin "$NEW_VERSION" || git push --force origin "$NEW_VERSION"
 }
 
+verify_binary_version() {
+    local bin_path="$1"
+    local expected="$2"
+
+    if [[ ! -x "$bin_path" ]]; then
+        print_error "Binary not found or not executable: $bin_path"
+        return 1
+    fi
+
+    local got
+    got="$($bin_path --version 2>/dev/null | awk '{print $2}')"
+    if [[ "$got" != "$expected" ]]; then
+        print_error "Binary version mismatch for $(basename "$bin_path"): expected $expected, got ${got:-<unknown>}"
+        return 1
+    fi
+
+    return 0
+}
+
 build_release_binary() {
     if [[ ! -f "build_static.sh" ]]; then
         print_error "build_static.sh not found"
         return 1
     fi
 
+    # Prevent stale artifacts from previous builds being uploaded.
+    rm -f build/nsigner_static_x86_64 build/nsigner_static_arm64
+
     ./build_static.sh > /dev/null 2>&1 || return 1
+    verify_binary_version "build/nsigner_static_x86_64" "$NEW_VERSION" || return 1
+
     ./build_static.sh --arch arm64 > /dev/null 2>&1 || print_warning "ARM64 build failed (continuing)"
+    if [[ -x "build/nsigner_static_arm64" ]]; then
+        verify_binary_version "build/nsigner_static_arm64" "$NEW_VERSION" || return 1
+    fi
+
     return 0
 }
 
@@ -253,9 +281,12 @@ main() {
             git tag "$NEW_VERSION" > /dev/null 2>&1
         fi
 
-        git_commit_and_push_no_tag
+        if ! build_release_binary; then
+            print_error "x86_64 release build failed; aborting release before push/upload"
+            exit 1
+        fi
 
-        build_release_binary || print_warning "x86_64 build failed"
+        git_commit_and_push_no_tag
 
         local binary_path_x86="build/nsigner_static_x86_64"
         local binary_path_arm64="build/nsigner_static_arm64"

install_qube_fips_nsigner.sh

@@ -110,6 +110,32 @@ download_nsigner_asset_url() {
     | head -n1 || true
 }
 
+verify_installed_version() {
+  local expected="$1"
+  local got_line=""
+  local got_ver=""
+
+  if [[ ! -x "${PREFIX_BIN}/nsigner" ]]; then
+    err "Installed binary missing: ${PREFIX_BIN}/nsigner"
+    exit 1
+  fi
+
+  got_line="$("${PREFIX_BIN}/nsigner" --version 2>/dev/null || true)"
+  got_ver="$(printf '%s\n' "${got_line}" | awk '{print $2}')"
+
+  if [[ -z "${got_ver}" ]]; then
+    err "Could not determine installed n_signer version from: ${got_line}"
+    exit 1
+  fi
+
+  if [[ "${got_ver}" != "${expected}" ]]; then
+    err "Downloaded binary version mismatch: expected ${expected}, got ${got_ver}"
+    err "Release asset appears stale or mislabeled."
+    err "Use NSIGNER_BINARY_URL to pin a known-good binary, or wait for a rebuilt release artifact."
+    exit 1
+  fi
+}
+
 install_nsigner() {
   local release_page=""
 
@@ -137,6 +163,8 @@ install_nsigner() {
     curl -fL -o "${PREFIX_BIN}/nsigner" "${asset_url}"
   fi
   chmod 0755 "${PREFIX_BIN}/nsigner"
+
+  verify_installed_version "${NSIGNER_VERSION}"
   log "Installed ${PREFIX_BIN}/nsigner from release binary"
 }
 

plans/auth_envelope_other_transports.md

@@ -0,0 +1,271 @@
+# Plan: Where else does the Schnorr auth envelope earn its keep?
+
+Status: **draft v1 — design exploration, for review**
+
+> **Origin.** [`plans/caller_token_identity.md`](caller_token_identity.md) introduced a per-request, BIP-340-Schnorr-signed *auth envelope* (Nostr kind 27235) that gives the TCP transport an application-layer identity. The TCP plan was deliberate about scope: AF_UNIX and qrexec keep their kernel/hypervisor identities, stdio inherits them, and the envelope is gated to TCP only. This document asks the next obvious question — **for which other transports is the same envelope actually useful, and where is it noise or worse?** — and proposes a small, conservative extension.
+
+The thesis up front: **the envelope is a tool for binding a stable program identity to a stream that the OS/hypervisor cannot itself attribute to a program**. Anywhere the OS already names the caller better than a pubkey could, the envelope adds attack surface for no gain. Anywhere the OS names a *machine* (uid, qube name) but cannot tell us *which program inside that machine*, the envelope earns its keep.
+
+---
+
+## 1. The framework: a 2x2 of what the substrate vouches for
+
+Every transport `n_signer` supports today, or might support tomorrow, can be classified along two axes:
+
+| | Substrate names a **principal** (uid, qube, account) | Substrate does **not** name a principal |
+|---|---|---|
+| **Substrate names a specific program** | A. Both. Strongest. | (impossible — naming a program implies naming its principal) |
+| **Substrate names only a machine/account, not a program** | B. Principal-only. The "which program" gap. | C. Anonymous pipe. |
+
+- **A** is hypothetical for our context. Not even AF_UNIX gives us this — `SO_PEERCRED.pid` is UX, not identity, because PIDs are reusable and the kernel does not bind PID to executable.
+- **B** is where AF_UNIX, qrexec, and stdio-via-qrexec actually live today. We learn `uid:1000` or `qubes:foo`, but two different binaries running as the same uid in the same qube look identical.
+- **C** is plain TCP, anonymous pipes, USB serial, Bluetooth — substrates that say only "some bytes arrived from somewhere."
+
+**The auth envelope's job is to upgrade B → A and C → A** by letting the program-with-a-keypair speak for itself, on top of whatever the substrate already provides. It does *not* replace substrate identity; it composes with it.
+
+This re-framing is the whole answer to the user's question. Every transport below is just a worked example of which cell it lives in.
+
+---
+
+## 2. Per-transport verdict
+
+| Transport | Substrate identity | Cell | Envelope verdict |
+|---|---|---|---|
+| AF_UNIX (current) | `SO_PEERCRED.uid` (kernel-attested) | B | **Optional, off by default.** Adds program-level identity inside one uid; useful for multi-program desktops, redundant for single-user vault qubes. |
+| qrexec (current) | `QREXEC_REMOTE_DOMAIN` (Xen-attested) | B | **Optional, off by default, but the most interesting case.** Solves the "many tools in one caller qube share one approval row" problem and the cross-qube state continuity question. See §3. |
+| stdio (current, interactive) | inherited uid of launching shell | B | **Off.** The user is at the terminal; substrate identity is the human, and the envelope cannot improve on that. |
+| stdio (current, qrexec-launched) | `QREXEC_REMOTE_DOMAIN` from env | B | **Same as qrexec row.** stdio over qrexec is qrexec by another name. |
+| stdio (anonymous pipe, e.g. systemd socket-activated, or shelled out from a daemon) | none | C | **Required if used in production.** No principal at all otherwise. See §4. |
+| TCP (implemented v2) | peer addr (forgeable beyond loopback) | C | **Required, on every request.** Already shipped; this plan does not modify it. |
+| FIPS / serial-over-USB (planned) | device path; no principal | C | **Required.** Same reasoning as TCP — substrate provides confidentiality of the wire (in FIPS's case) but no caller identity. |
+| Bluetooth / NFC (hypothetical) | MAC address (forgeable) | C | **Required.** |
+
+The verdict column collapses to three modes — **off**, **optional** (accepted if present, ignored if absent), **required** (rejected if absent) — selectable per listener.
+
+---
+
+## 3. The qrexec story (the user's actual question)
+
+Qubes is the case where the envelope buys the most, and where it most clearly solves a problem the user has named: *"keeping state between qubes is difficult."* Two distinct sub-problems hide under that phrase. The envelope addresses one of them cleanly and the other partially.
+
+### 3.1 Sub-problem 1: many programs, one approval row
+
+A typical caller qube — say `personal` — runs nostr_terminal, a browser extension, a CLI scratch tool, and a backup script. Today they all show up to the signer as `qubes:personal`. The user approves once, and from then on **every program in that qube is a signer for that nostr_index**. There is no way to express "the browser extension may sign kind-1 events but the CLI scratch tool may not." Approval granularity is one-per-qube, which is too coarse for any caller qube that holds more than one tool.
+
+With the envelope optional-on for qrexec:
+
+- nostr_terminal in `personal` signs envelopes with its caller pubkey `Pk_term`. Browser extension signs with `Pk_ext`. The signer records *two distinct caller_ids* — `qubes:personal+pubkey:<Pk_term>` and `qubes:personal+pubkey:<Pk_ext>` (composite form, see §6) — and prompts once per program.
+- Programs that send no envelope keep the legacy `qubes:personal` identity and the legacy approval row. Backwards compatible.
+- The user gets per-program revocation: removing the approval for `Pk_ext` does not affect nostr_terminal, even though both run inside `personal`.
+
+This is the same connection-churn fix the TCP plan delivered, applied to a different ambiguity: not "same network address, different process" but "same qube, different program." The fix is identical because the underlying gap is identical — the substrate names something coarser than the unit we want to authorize.
+
+### 3.2 Sub-problem 2: state continuity between qubes
+
+In Qubes, programs that want shared identity across qubes — say a tool the user runs in both `personal` and `work`, or a tool installed in a disposable that is recreated each launch — cannot use any of the usual "save a token to disk" tricks because the qubes are separate state domains. The qrexec policy can route the call but cannot share secrets.
+
+The envelope does not magically share state across qubes — but **it makes the question well-formed**. Two patterns become available:
+
+- **Per-qube installation, distinct identity.** Tool `T` installed in `personal` generates its own keypair on first run, stored in that qube. Tool `T` in `work` generates a different keypair. The signer sees two callers; the user approves each. This is exactly what the security model wants — the qubes are *different trust domains*, so they should have different identities, full stop.
+- **Per-tool identity, shared across qubes via deliberate seed copy.** A power user who genuinely wants "the same identity for nostr_terminal in `personal` and `work`" can copy nostr_terminal's seed (or derived caller key) between the two qubes themselves, using Qubes' usual file-copy primitives. The signer then sees one caller identity from two qubes. Whether that is a good idea is a user-policy decision; the protocol simply tolerates it.
+
+The disposable-VM case is the most interesting. A disposable that re-rolls its caller keypair on every boot will re-prompt the signer every boot — which is correct behavior. *"This is a fresh untrusted environment"* is exactly what a disposable is. If the user wants disposable-but-recognized, they are asking for the per-tool seed pattern above and have to accept the tradeoff that the seed material outlives the disposable.
+
+The envelope does not solve cross-qube state by itself. What it does is **give the user a stable, signer-visible name to make their state-management decisions against** — instead of forcing every cross-qube identity question through the qube-name primitive, which is too coarse to express the question.
+
+### 3.3 Why "optional, off by default" rather than "required"
+
+Required envelopes for qrexec would break every existing caller (shell scripts, the existing client examples in [`documents/qubes_client_examples.md`](../documents/qubes_client_examples.md)) and force every Qubes caller to grow Schnorr-signing capability before it can talk to the signer. That is too high a cost for a transport whose substrate identity is already strong.
+
+Optional means:
+
+- Old callers keep working unchanged. Their `caller_id` stays `qubes:<vm>`.
+- New callers that *want* per-program approvals send envelopes and get `qubes:<vm>+pubkey:<hex>`.
+- Operators who want to enforce envelope-on-qrexec for a hardened deployment can flip a flag (`--qrexec-require-auth`).
+
+The default-off posture matches the TCP plan's principle: *give the weakest substrate the strongest application-layer identity.* qrexec is not the weakest; it is the second-strongest. It earns the upgrade only where the operator opts in.
+
+---
+
+## 4. The stdio story
+
+stdio mode in `n_signer` has three real-world spawning patterns:
+
+1. **Interactive: a user runs `nsigner --listen stdio` in a terminal and pipes a request in.** Substrate identity is the user's own uid. The user is physically present at the prompt anyway. **Envelope adds nothing.** Off.
+
+2. **qrexec service: stdio with `QREXEC_REMOTE_DOMAIN` set.** Already covered as the qrexec row in §2. Same verdict as qrexec.
+
+3. **Spawned by another program over an anonymous pipe.** Daemon `D` execs `nsigner --listen stdio` and pipes JSON-RPC over the inherited fds. The signer sees only `STDIN_FILENO`; there is no `SO_PEERCRED` (no socket), no `QREXEC_REMOTE_DOMAIN`, no peer address. Today the signer falls back to its own uid as caller_id, which is to say *the signer is its own caller* — meaningless as identity. **This is cell C.** If anyone is using this pattern, the envelope is the only available identity primitive.
+
+The third pattern is rare but not hypothetical. systemd socket-activated services, container init wrappers, and "supervisor that spawns one signer process per request" deployments all fit. Today they are silently insecure (any program in the same uid can pipe a request in and be `caller_id = uid:1000`, indistinguishable from any other). With envelope-required for anonymous-pipe stdio, the daemon must hold a keypair and identify itself, and the signer can record per-daemon approvals.
+
+The detection rule is mechanical: if the listen mode is stdio AND `QREXEC_REMOTE_DOMAIN` is unset AND `SO_PEERCRED` is unavailable on stdin (it is not a socket), classify the stream as anonymous-pipe stdio and require the envelope. Two existing pieces of code already participate in this branch: [`server_get_caller`](../src/server.c:1181) for the QREXEC env check, and the listen-mode plumbing in [`src/main.c:1043`](../src/main.c:1043).
+
+---
+
+## 5. The AF_UNIX story (briefly)
+
+AF_UNIX is the strongest substrate today and the one most likely to be misjudged. It is tempting to say "uid is enough." For single-user vault qubes it is. For shared workstations or for the per-program-revocation use case described in §3.1, it is not.
+
+The right disposition for AF_UNIX is identical to qrexec: **optional envelope, off by default, on-flag to require**. Same composite caller_id form. The only difference is that the prompt UX should still surface `pid=N (exe=/path)` from `SO_PEERCRED` as decoration alongside the npub, because on a local machine the user can `ps -p N` to verify in a way they cannot for a remote pubkey.
+
+This was [`plans/caller_token_identity.md`](caller_token_identity.md) §13 open question 5 ("should AF_UNIX accept an envelope as additional identity?") with the v2 default of "no." This document **revisits that default** and proposes "yes, but optional." See §6 and §8.
+
+---
+
+## 6. Composite caller_id form
+
+When envelope is **optional and present** on a non-TCP transport, the caller_id needs to combine substrate identity and pubkey identity. The proposed form:
+
+```
+qubes:personal+pubkey:abc123…def
+uid:1000+pubkey:abc123…def
+anon-stdio+pubkey:abc123…def      ; for case §4.3
+```
+
+Properties:
+
+- **Lexicographic prefix matches substrate-only callers.** A policy entry for `qubes:personal` does **not** match `qubes:personal+pubkey:…` — they are distinct strings, distinct rows. This is intentional: opting into envelope auth means opting into a new, separate identity, not "same identity but with extra proof."
+- **The plus character is illegal in every existing caller_id form** (uids are digits, pubkeys are hex, qube names are alphanumeric+hyphen). Using `+` as separator avoids ambiguity.
+- **Width.** `caller_id` was widened to 80 bytes in v2 of the TCP plan ([`plans/caller_token_identity.md:181`](caller_token_identity.md:181)). The composite form needs `len("qubes:") + 64 + len("+pubkey:") + 64 + 1` ≈ 144 bytes. Bumps to 160 to round.
+
+Approvals attach to the composite string. A user who approves the composite form is approving "this program *running in* this qube," not "this program anywhere" and not "this qube's anything." That is the correct semantics for the per-program-revocation use case.
+
+For TCP — where substrate identity does not exist — the form remains the bare `pubkey:<hex>` from v2. No change.
+
+---
+
+## 7. Wire-protocol changes (small)
+
+The existing envelope already carries everything needed; only the verification gate changes per transport.
+
+### 7.1 Per-listener auth posture
+
+Three settings, one per listener:
+
+| Posture | Behavior on receipt |
+|---|---|
+| `off` | `auth` field, if present, is **ignored**. caller_id is substrate-only. Default for AF_UNIX, qrexec, interactive stdio. |
+| `optional` | If `auth` is present and verifies → composite caller_id. If `auth` is absent → substrate-only caller_id. If `auth` is present and fails verification → reject. Operator opt-in for AF_UNIX/qrexec/stdio. |
+| `required` | `auth` must be present and verify. Default for TCP, FIPS-serial, anonymous-pipe stdio. |
+
+CLI plumbing extends what the TCP plan already added:
+
+```
+--listen unix --auth off            # default
+--listen unix --auth optional
+--listen qrexec --auth optional
+--listen stdio --auth required      # for anon-pipe deployments
+--listen tcp:... --auth required    # only legal value for tcp; kept explicit
+```
+
+The auth-skew-seconds and nonce cache are listener-context state; they already exist in `server_ctx_t` from v2 and are reused unmodified.
+
+### 7.2 The envelope itself: zero changes
+
+Same kind 27235, same three required tags, same JCS body hash, same Schnorr verification primitive [`nostr_verify_event_signature`](../resources/nostr_core_lib/nostr_core/nip001.h:20). A client that signs envelopes for TCP today can sign them for qrexec tomorrow with no code change. This is the single most important property of the proposal — it preserves the v2 envelope as a portable, transport-independent artifact.
+
+### 7.3 Replay cache scoping
+
+One subtle question: is the nonce cache per-listener or process-global? Process-global is simpler and strictly stricter (an envelope replayed across two listeners is also rejected). Per-listener is more permissive but has no real attack-model justification. **Default: process-global**, unchanged from v2.
+
+---
+
+## 8. Decision matrix and recommended defaults
+
+| Transport | Default posture | Operator can flip to | Rationale |
+|---|---|---|---|
+| AF_UNIX | off | optional, required | uid is strong; envelope is for power users who need per-program granularity. |
+| qrexec | off | optional, required | qube is strong; envelope solves §3.1 for users who hit it. |
+| stdio (interactive) | off | (locked off) | Envelope cannot improve on a human at the terminal. |
+| stdio (qrexec-launched) | inherits qrexec posture | (inherits) | Same substrate. |
+| stdio (anonymous pipe) | required | (locked required) | No substrate identity exists; refusing is the only safe default. |
+| TCP | required | (locked required) | Already v2 default. Unchanged. |
+| FIPS / USB-serial (planned) | required | (locked required) | Same as TCP — wire identity is fictional. |
+
+"Locked" rows reflect transports where flipping the posture would re-introduce the gap the envelope was designed to close, and the CLI rejects the change.
+
+---
+
+## 9. Implementation order
+
+Each step is independently mergeable, gated behind the per-listener `--auth` flag default of `off` for the new transports so existing callers see no behavior change.
+
+1. **Refactor: lift the v2 auth gate out of the TCP-specific branch in [`server_handle_one`](../src/server.c:1192) into a transport-agnostic helper** parameterized by posture. No semantic change yet; TCP listener still passes `required`.
+2. **Add the `--auth {off|optional|required}` CLI flag** with per-listener storage on `server_ctx_t`. Default off for unix/qrexec, required for tcp, off-locked for interactive stdio, required-locked for anonymous-pipe stdio.
+3. **Add anonymous-pipe-stdio detection.** In [`server_get_caller`](../src/server.c:1181), when listen mode is stdio and `QREXEC_REMOTE_DOMAIN` is unset, probe `SO_PEERCRED` on stdin; on failure mark the stream as anonymous-pipe and require auth.
+4. **Composite caller_id format** in [`caller_identity_t`](../src/server.c:404). Widen to 160. Add a small helper `caller_id_compose(buf, sz, substrate_kind, substrate_value, pubkey_hex)`.
+5. **`--preapprove` extension.** Accept the composite form (`caller=qubes:personal+pubkey:<hex>`, `caller=uid:1000+pubkey:<hex>`). Existing forms stay valid.
+6. **Tests.**
+   - Optional-mode AF_UNIX accepting both with-envelope and without-envelope requests, producing two distinct caller_ids.
+   - Optional-mode qrexec with two distinct pubkeys from one source qube → two prompts, two approvals, independent revocation.
+   - Anonymous-pipe-stdio rejects no-envelope requests with code 2014.
+   - TCP behavior unchanged (regression check on v2).
+7. **Documentation.**
+   - [`documents/SECURITY.md`](../documents/SECURITY.md) §3 identity table: add the composite kinds; clarify that envelope is now a portable identity layer, not a TCP-only feature.
+   - [`documents/QUBES_OS.md`](../documents/QUBES_OS.md): add a §3.4 on per-program identity within a qube and the disposable-VM tradeoff.
+   - [`documents/CLIENT_IMPLEMENTATION.md`](../documents/CLIENT_IMPLEMENTATION.md): note that any client may attach an envelope on any transport; the signer's posture decides whether it is honored or required.
+
+## 10. What this plan deliberately does not do
+
+- **Does not change TCP behavior.** The v2 contract on TCP — required envelope, every request — is preserved exactly.
+- **Does not introduce a new envelope format, kind, or canonicalization.** Reuses kind 27235 and the JCS body-hash rule from v2 verbatim.
+- **Does not propose persistent state** anywhere. Approvals stay in RAM; no caller registry on disk; the §1 "crash equals total wipe" property of [`documents/SECURITY.md:19`](../documents/SECURITY.md:19) is unchanged.
+- **Does not invent an answer to cross-qube state continuity.** It articulates the question and gives the user a primitive (a stable pubkey-named caller) against which to make their own state decisions.
+- **Does not add transport encryption** for any substrate. Confidentiality is the substrate's job (FIPS, qrexec, AF_UNIX with abstract namespace, loopback). The envelope is auth, not encryption.
+
+## 11. Open questions for review
+
+1. **Is the composite caller_id form (`substrate+pubkey:...`) the right disposition, or should the envelope, when present, *override* substrate identity entirely (replacing rather than composing)?** The override form is simpler — one identity, not two — but it discards information the user might want (the npub is verified; the qube name is hypervisor-attested; both data points are useful at the prompt). Default: compose.
+2. **Should anonymous-pipe stdio be required or rejected outright?** A reasonable case can be made that `nsigner --listen stdio` over a non-tty, non-socket fd is just *misuse* and should refuse to start rather than silently demand envelopes. Default: require envelope; allow operator to disable the listen mode entirely if undesired.
+3. **Should the `--auth optional` setting on AF_UNIX/qrexec be a per-listener flag (today's proposal) or per-method (e.g. envelope required for `sign_event` but not for `get_public_key`)?** Per-method adds policy surface for limited gain; substrate identity is already the per-method gate via the existing role table. Default: per-listener only.
+4. **Does the v2 nonce cache size of 1024 still suffice when up to four listeners may share it?** Yes — the bound is "envelopes per skew window," not "listeners." Confirmed sufficient. No change.
+5. **Should `qubes:<vm>+pubkey:<hex>` and `pubkey:<hex>` (TCP) for the same pubkey be considered the same caller for `--preapprove` convenience?** No. They are different identities by construction (different substrates, different threat models). An operator who wants both pre-approved writes both lines. Default: keep them distinct.
+
+---
+
+## Appendix A — Mermaid: revised per-transport decision tree
+
+```mermaid
+flowchart TD
+    A[Request arrives on a listener] --> B{listener auth posture}
+    B -- off --> C[ignore any auth field]
+    C --> D[caller_id = substrate-only]
+    B -- optional --> E{auth field present?}
+    E -- no --> D
+    E -- yes --> F[verify envelope per v2 rules]
+    F -- fail --> G[reject 2010-2017]
+    F -- ok --> H[caller_id = substrate + pubkey:hex]
+    B -- required --> I{auth field present?}
+    I -- no --> J[reject 2014 auth_envelope_required]
+    I -- yes --> F
+    D --> K[normal policy_check]
+    H --> K
+    K --> L{verdict}
+    L -- ALLOW --> M[dispatch RPC]
+    L -- DENY --> N[2001 policy_denied]
+    L -- PROMPT --> O[approve / save / register caller_id]
+    O --> M
+```
+
+## Appendix B — Worked example: per-program identity inside a qube
+
+Caller qube `personal` runs two tools:
+
+- nostr_terminal, holding caller key `Pk_term`.
+- A custom shell script, no keypair.
+
+Operator starts the signer with:
+
+```
+nsigner --listen qrexec --auth optional \
+  --preapprove caller=qubes:personal+pubkey:Pk_term,role=main
+```
+
+First request from nostr_terminal carries an envelope signed by `Pk_term`. Signer verifies, builds caller_id `qubes:personal+pubkey:Pk_term`, hits the pre-approval, signs without prompting.
+
+First request from the shell script carries no envelope. Signer skips verification, builds caller_id `qubes:personal`, finds no approval, prompts the user. User can approve `[a]` for the shell script independently of nostr_terminal.
+
+Later, the user wants to revoke the shell script's access (a future TUI hotkey). They remove the `qubes:personal` row. nostr_terminal continues to work because its row `qubes:personal+pubkey:Pk_term` is untouched. **Per-program revocation, achieved without any change to qrexec policy or the qube boundary.**
+
+This is the concrete answer to the user's "is this useful for other transports" question — yes, in qrexec specifically, where it converts qube-granularity approvals into program-granularity approvals while leaving the qube boundary itself unchanged.

plans/caller_token_identity.md

@@ -0,0 +1,483 @@
+# Plan: Caller-pubkey identity with required Schnorr authentication for URL/TCP
+
+Status: **draft v2 — for review**
+
+> **History.** Draft v1 of this document proposed a random 32-byte bearer token persisted to a `0600` file on both ends. That draft was rejected on two grounds: (1) it violated [`documents/SECURITY.md:19`](../documents/SECURITY.md:19) — "Crash equals total wipe" — by writing tokens to disk, and (2) bearer credentials over a transport already chosen as the *least* trusted is the wrong security gradient. v2 replaces the bearer token with a Schnorr-authenticated public key, removes all disk persistence, and requires cryptographic proof-of-possession on every TCP/URL request from day one.
+
+This plan addresses the same originating bug — every TCP reconnect re-fires the approval prompt because `caller_id` is built from the ephemeral `addr:port` pair — but does so by giving the weakest transport the strongest application-layer identity, not the weakest. AF_UNIX and qrexec retain their existing kernel- and hypervisor-vouched identities; TCP/URL gains BIP-340 Schnorr authentication using primitives the signer already links.
+
+---
+
+## 1. Goals
+
+1. **One approval per program-keypair, not per TCP connection.** Two requests carrying the same `caller_pubkey` resolve to the same policy entry regardless of source port, transport jitter, or reconnect.
+2. **Cryptographic proof-of-possession on every TCP/URL request.** The wire identity is not just a name; it is backed by a signature that only the holder of the corresponding private key can produce.
+3. **Replay-resistant within a bounded window.** A captured request cannot be replayed against the signer indefinitely.
+4. **No disk persistence — anywhere.** No tokens on disk, no caller registry on disk, no policy on disk. "Crash equals total wipe" applies to this feature unmodified.
+5. **Stronger transports keep their stronger primitives.** AF_UNIX still uses `SO_PEERCRED`; qrexec still uses `QREXEC_REMOTE_DOMAIN`. Neither acquires a new spoofable claim field, and neither is required to send signatures.
+6. **Use only `nostr_core_lib` and existing dependencies.** No new crypto libraries. No new hash functions. The auth envelope is a Nostr event, verified by a primitive [`nostr_verify_event_signature`](../resources/nostr_core_lib/nostr_core/nip001.h:20) the signer already trusts.
+
+## 2. Non-goals
+
+- **No transport-level encryption / TLS.** FIPS still provides confidentiality of the substrate. Application-layer auth and transport encryption are separate concerns.
+- **No mutual authentication of the signer to the client.** This plan authenticates the client to the signer. The reverse direction is future work and intentionally out of scope.
+- **No persistence of any state.** Approvals stay in RAM. A signer restart re-prompts every caller exactly once. A client restart re-prompts itself once if it lost its in-memory keypair, or zero times if the client retains its own identity in its own memory.
+- **No new transports.** AF_UNIX, qrexec, stdio, TCP unchanged at the socket layer.
+- **No PID-as-identity.** Documented rejection in §10.
+- **No bearer tokens.** Explicit reversal of v1.
+- **No change to the deny-by-default rule.** A new pubkey shows up exactly once at the prompt; everything in [`plans/deny_by_default_approvals.md`](deny_by_default_approvals.md) applies unchanged.
+
+## 3. The model in one paragraph
+
+For TCP/URL transport, every JSON-RPC request must carry an **auth envelope** — a small Nostr-shaped event signed by the caller's private key. The signer verifies that signature with [`nostr_verify_event_signature`](../resources/nostr_core_lib/nostr_core/nip001.h:20) before any policy logic runs. The verified `pubkey` field becomes the `caller_id` for that request (`pubkey:<hex>` form), feeding straight into the existing policy table that already handles `uid:1000`, `qubes:foo`, `tcp:[addr]:port`. On first contact for a given pubkey, the existing deny-by-default prompt fires; the user sees the npub, an optional client-supplied label, and the verb/role; on `[a]` the pubkey is recorded as an approval entry the same way any other caller is. Subsequent requests from the same pubkey hit the approval and are served silently. AF_UNIX and qrexec are unaffected — they continue to use kernel/hypervisor identity and ignore any auth envelope they receive. Nothing is written to disk on either side at any point.
+
+## 4. Concept additions to the existing model
+
+[`documents/SECURITY.md:57`](../documents/SECURITY.md:57) defines three concepts: identity, index, approval. This plan adds nothing visible to the user beyond an alternate identity *kind*. There is no fourth concept. Specifically:
+
+- A **pubkey-identified caller** is a new identity kind, alongside `unix_peer`, `qubes`, `tcp_local`, `tcp_remote`. Its `caller_id` form is `pubkey:<64 hex chars>`.
+- An **auth envelope** is a wire-protocol artifact, not a user-facing concept. The user never sees the word "envelope"; they see "caller: npub1abc…xyz" at the prompt.
+- An **approval** is unchanged: the same `(caller_id, role) → PROMPT_NEVER` row in the same in-memory policy table.
+
+The only document-level change is that [`documents/SECURITY.md`](../documents/SECURITY.md) §11's "tcp_remote (planned)" and "fips (planned)" rows ([`documents/SECURITY.md:98-99`](../documents/SECURITY.md:98)) become "implemented; identity = caller pubkey verified by Schnorr signature."
+
+## 5. Per-transport identity primitives — the unified picture
+
+| Transport | Identity primitive | Validation | `caller_id` form | Auth envelope required? |
+|---|---|---|---|---|
+| AF_UNIX | `SO_PEERCRED.uid` (and `pid` for UX) | Kernel-attested. | `uid:<n>` | **No.** Kernel vouches. |
+| qrexec | `QREXEC_REMOTE_DOMAIN` | Hypervisor-attested. | `qubes:<vm>` | **No.** Xen vouches. |
+| stdio | inherited environment (qrexec or interactive) | As above. | `qubes:<vm>` or `uid:<n>` | **No.** |
+| TCP / FIPS | `caller_pubkey` from auth envelope | BIP-340 Schnorr signature verified by `nostr_verify_event_signature`. | `pubkey:<hex>` | **Yes. Required on every request.** |
+
+A TCP request that arrives **without** a valid auth envelope is rejected before any policy logic runs. There is no fallback to `tcp:[addr]:port` identity; v2 retires that form entirely for the TCP listener. Operators who relied on `--preapprove caller=tcp:...` must migrate to `--preapprove caller=pubkey:<hex>` (see §7.5).
+
+## 6. Wire protocol: the auth envelope
+
+### 6.1 Shape
+
+The auth envelope is a single JSON object placed at the top level of the request, alongside (not inside) `method`/`params`. It is structured exactly like a NIP-01 Nostr event so that [`nostr_verify_event_signature`](../resources/nostr_core_lib/nostr_core/nip001.h:20) verifies it directly with no custom canonicalization code on the signer side:
+
+```json
+{
+  "id": "rpc-42",
+  "method": "sign_event",
+  "params": { ... },
+  "auth": {
+    "id":         "<32-byte event id, hex>",
+    "pubkey":     "<32-byte x-only secp256k1 pubkey, hex>",
+    "created_at": 1730000000,
+    "kind":       27235,
+    "tags":       [
+      ["nsigner_rpc", "rpc-42"],
+      ["nsigner_method", "sign_event"],
+      ["nsigner_body_hash", "<sha256(canonical body), hex>"]
+    ],
+    "content":    "<optional client label, e.g. \"nostr_terminal@laptop\">",
+    "sig":        "<64-byte Schnorr signature, hex>"
+  }
+}
+```
+
+The `kind` value `27235` is the same kind NIP-42 uses for client authentication to relays. We are explicitly piggybacking on that semantic: this is "client authenticates to a service it wants to use," and reusing the existing kind keeps us inside Nostr conventions rather than inventing a new event kind. The signer accepts kind 27235 events whose tag set marks them as nsigner-bound.
+
+### 6.2 Required tags
+
+Three tags are required on every envelope. The signer rejects envelopes missing any of them with `auth_envelope_malformed` (code 2010).
+
+| Tag name | Value | Purpose |
+|---|---|---|
+| `nsigner_rpc` | The request's `id` field, copied verbatim. | Binds the signature to this specific request id; a captured envelope cannot be reused with a different request id. |
+| `nsigner_method` | The request's `method` field, copied verbatim. | Binds the signature to the verb. A captured `get_public_key` envelope cannot be replayed as `sign_event`. |
+| `nsigner_body_hash` | Hex SHA-256 of the canonicalized `params` object — see §6.3. | Binds the signature to the request payload. The signer recomputes this hash and rejects on mismatch with `auth_body_mismatch` (code 2011). |
+
+### 6.3 Canonicalization of `params`
+
+To make `nsigner_body_hash` deterministic across implementations, `params` must be hashed in a single canonical form. To avoid inventing a new canonicalizer, we adopt **JCS** (RFC 8785, JSON Canonicalization Scheme) — the same canonicalization Nostr already uses for event IDs in NIP-01. The body hash is `SHA-256(JCS(params))`, computed by both client and signer using [`nostr_sha256`](../resources/nostr_core_lib/nostr_core/utils.h:46).
+
+If `params` is absent from the request, `nsigner_body_hash` is `SHA-256("null")` (the canonicalization of JSON `null`), which is a fixed 64-char constant the signer can use without per-request hashing for the no-params case.
+
+### 6.4 Signature verification
+
+On receipt of a TCP request, the signer:
+
+1. Extracts the `auth` object. If absent, reject with `auth_envelope_required` (code 2014).
+2. Validates the envelope is structurally a NIP-01 event (id is sha256 of canonical event header; `pubkey`, `sig`, `created_at`, `kind`, `tags`, `content` present and well-typed). Library function [`nostr_validate_event_structure`](../resources/nostr_core_lib/nostr_core/nip001.h:19) handles this.
+3. Verifies the Schnorr signature: [`nostr_verify_event_signature(auth_event)`](../resources/nostr_core_lib/nostr_core/nip001.h:20). Reject with `auth_signature_invalid` (code 2012) on failure.
+4. Checks `kind == 27235`. Reject with `auth_kind_invalid` (code 2013) otherwise.
+5. Confirms `nsigner_rpc` tag matches request `id` and `nsigner_method` tag matches request `method`. Reject with `auth_envelope_mismatch` (code 2015) on either mismatch.
+6. Computes `SHA-256(JCS(params))` and confirms it matches `nsigner_body_hash`. Reject with `auth_body_mismatch` (code 2011) on mismatch.
+7. Applies replay protection — see §6.5.
+8. On success, sets `caller.caller_id = "pubkey:" + hex(pubkey)`. Policy lookup proceeds against this caller_id.
+
+### 6.5 Replay protection
+
+Two layered defenses, neither requiring disk:
+
+#### 6.5.1 Timestamp window
+
+`auth.created_at` must satisfy `|now - created_at| <= AUTH_CLOCK_SKEW_SEC`. Default `AUTH_CLOCK_SKEW_SEC = 30`. Configurable via `--auth-skew-seconds` at startup. Reject with `auth_envelope_stale` (code 2016) if outside the window.
+
+The 30-second window is small enough that a captured envelope is a poor reuse target and large enough to tolerate ordinary clock drift in the FIPS-mediated path. Operators with looser requirements can widen it; operators with NTP-locked deployments can narrow it.
+
+#### 6.5.2 Nonce / id cache
+
+The signer maintains an in-memory ring buffer of recently-seen `auth.id` values:
+
+```c
+#define AUTH_NONCE_CACHE_SIZE 1024
+typedef struct {
+    uint8_t  id[32];
+    uint64_t seen_at;        /* monotonic seconds */
+} auth_nonce_entry_t;
+
+typedef struct {
+    auth_nonce_entry_t entries[AUTH_NONCE_CACHE_SIZE];
+    int head;
+    int count;
+} auth_nonce_cache_t;
+```
+
+On verified envelope, the signer linearly scans the cache for `auth.id`. If found, reject with `auth_replay_detected` (code 2017). If not, insert at head, evicting the tail if full.
+
+The cache size of 1024 paired with the 30-second window means at sustained 33+ requests/second from any caller would push older entries out before they expire — at which point the timestamp window catches the replay anyway. The two defenses overlap intentionally: the cache catches fast replays inside the window; the timestamp catches slow replays outside it.
+
+The cache is purely in-memory. On signer restart it starts empty, which is safe because the timestamp window also resets the universe of acceptable envelopes — any envelope created before the restart is now outside the window and would be rejected on `created_at` grounds before reaching the nonce check.
+
+### 6.6 Error codes added
+
+| Code | Symbolic name | Meaning |
+|---|---|---|
+| 2010 | `auth_envelope_malformed` | Required field or tag missing / wrong type. |
+| 2011 | `auth_body_mismatch` | `nsigner_body_hash` did not match recomputed hash of `params`. |
+| 2012 | `auth_signature_invalid` | Schnorr verification failed. |
+| 2013 | `auth_kind_invalid` | Auth event kind ≠ 27235. |
+| 2014 | `auth_envelope_required` | TCP request arrived with no `auth` object. |
+| 2015 | `auth_envelope_mismatch` | `nsigner_rpc` or `nsigner_method` tag did not match request envelope. |
+| 2016 | `auth_envelope_stale` | `created_at` outside skew window. |
+| 2017 | `auth_replay_detected` | `auth.id` already seen in nonce cache. |
+
+These are placed in their own contiguous range so client code can identify "auth-layer error → bug in my signing code" vs "policy-layer error → user denied."
+
+## 7. Signer-side data model and code changes
+
+### 7.1 Extension to `caller_identity_t`
+
+[`src/server.c:404`](../src/server.c:404) currently has:
+
+```c
+typedef struct {
+    int kind;
+    char caller_id[64];
+    char source_qube[64];
+} caller_identity_t;
+```
+
+Becomes:
+
+```c
+typedef struct {
+    int     kind;
+    char    caller_id[80];                /* widened: "pubkey:" + 64 hex + NUL fits */
+    char    source_qube[64];
+    /* Filled in only when an auth envelope was verified on this request. */
+    int     auth_present;                 /* 0 or 1 */
+    uint8_t auth_pubkey[32];              /* present iff auth_present */
+    char    auth_label[64];               /* envelope `content` field, sanitized */
+    /* UX context, never used as policy key. */
+    pid_t   peer_pid;                     /* SO_PEERCRED.pid for AF_UNIX, else 0 */
+    char    peer_addr[64];                /* tcp:[...]:port, used in prompt context */
+} caller_identity_t;
+```
+
+The widened `caller_id` ripples through every translation unit's headerless declaration block. Mechanical change.
+
+### 7.2 New translation unit: `src/auth_envelope.c`
+
+A new file owns auth-envelope parsing, verification, and the nonce cache. Public surface:
+
+```c
+typedef enum {
+    AUTH_OK = 0,
+    AUTH_ERR_MALFORMED,
+    AUTH_ERR_BODY_MISMATCH,
+    AUTH_ERR_SIG_INVALID,
+    AUTH_ERR_KIND_INVALID,
+    AUTH_ERR_REQUIRED,
+    AUTH_ERR_TAG_MISMATCH,
+    AUTH_ERR_STALE,
+    AUTH_ERR_REPLAY
+} auth_result_t;
+
+/* Verify the auth envelope embedded in `request_root` against the request's
+ * id, method, and params. On AUTH_OK, fills caller->auth_pubkey and
+ * caller->auth_label. Does not touch caller_id. */
+auth_result_t auth_envelope_verify(cJSON *request_root,
+                                   auth_nonce_cache_t *nonce_cache,
+                                   int skew_seconds,
+                                   uint64_t now_unix,
+                                   caller_identity_t *caller);
+
+void auth_nonce_cache_init(auth_nonce_cache_t *cache);
+```
+
+The implementation is thin: extract `auth` cJSON object, run library validations, run our tag/body/replay checks, return. All the heavy crypto lifting is `nostr_verify_event_signature`.
+
+A corresponding [`tests/test_auth_envelope.c`](../tests/test_auth_envelope.c) covers the eight error paths with hand-crafted envelopes (using a fixed test keypair) and the happy path.
+
+### 7.3 Ordering in `server_handle_one`
+
+[`src/server.c:1192`](../src/server.c:1192) gains an auth gate between framed-receive and selector-resolve, but only on TCP. Pseudocode for the revised flow:
+
+```
+1. accept(); server_get_caller(fd, &caller);  /* unchanged: kind, peer_addr */
+2. transport_recv_framed(fd, &request);
+3. if (caller.kind == NSIGNER_LISTEN_TCP) {
+       parse request as cJSON;
+       auth_result = auth_envelope_verify(root, &ctx->nonce_cache,
+                                          ctx->auth_skew, now, &caller);
+       if (auth_result != AUTH_OK) { send error 2010-2017; close; return; }
+       snprintf(caller.caller_id, ..., "pubkey:%s", hex(caller.auth_pubkey));
+   }
+   /* AF_UNIX/qrexec: caller.caller_id already set; auth envelope, if any,
+      is silently ignored. */
+4. extract method + selector;  /* unchanged */
+5. resolve role;               /* unchanged */
+6. policy_check(caller.caller_id, ...);  /* unchanged */
+7. prompt if PROMPT;            /* unchanged */
+8. dispatch;                   /* unchanged */
+```
+
+The auth gate is a single function call. Existing code paths are touched only at the point where `caller.caller_id` is overwritten on success.
+
+### 7.4 Server context additions
+
+[`server_ctx_t`](../src/server.c) gains:
+
+```c
+auth_nonce_cache_t nonce_cache;   /* in-memory, zeroed at startup, never persisted */
+int auth_skew_seconds;            /* default 30, settable via --auth-skew-seconds */
+```
+
+### 7.5 `--preapprove` extension
+
+[`parse_preapprove_spec`](../src/policy.c:553) gains a new caller form:
+
+```
+--preapprove caller=pubkey:<64 hex>,role=main
+--preapprove caller=pubkey:<64 hex>,nostr_index=1
+```
+
+The pubkey is the **client's** caller pubkey — a 32-byte x-only secp256k1 hex value. No file reference; the operator has the pubkey directly. There is no `pubkey_file` form because the pubkey is not secret and embedding it in the unit file is fine.
+
+The `tcp:` caller form is **deprecated** for the TCP listener (not removed; AF_UNIX and qrexec preapprovals are unaffected — they never used `tcp:`). On a `--preapprove caller=tcp:...` for a TCP listener, the signer prints a deprecation warning at startup explaining that TCP requests now require auth envelopes and the entry will never match. This is documented in [`documents/N_OS_TR_AGENT_CHANGES.md`](../documents/N_OS_TR_AGENT_CHANGES.md).
+
+### 7.6 No persistence — confirmed property
+
+This plan introduces:
+- An in-memory `caller_identity_t` per request (already exists; widened).
+- An in-memory `auth_nonce_cache_t` per server context (new, ring buffer, RAM only).
+- New entries in the existing in-memory `policy_table_t` keyed on `pubkey:<hex>` (no schema change).
+
+It does **not** introduce:
+- Any file written by the signer.
+- Any file required at startup by the signer (beyond the already-required mnemonic input).
+- Any state that survives `server_stop`.
+
+"Crash equals total wipe" remains literally true.
+
+## 8. Client-side requirements (e.g. nostr_terminal)
+
+### 8.1 Caller keypair
+
+The client needs a secp256k1 keypair for the purpose of authenticating to n_signer. Three sourcing strategies are supported, and the choice is the client's:
+
+1. **Reuse the program's existing Nostr identity.** A program like nostr_terminal that already has a published Nostr pubkey can use that same keypair as its caller identity. The user sees a familiar npub at the prompt and recognizes "yes, that's nostr_terminal's pubkey."
+2. **Derive a dedicated caller identity from the program's seed.** A program with a stored seed can derive a separate `m/44'/1237'/<n>'/0/<m>` key as a stable "RPC client identity" distinct from its public posting key. The user sees a unique-to-the-program-installation npub.
+3. **Generate ephemerally per session.** A program that has no persistent identity at all generates a fresh secp256k1 key in memory at startup. Each client restart yields a new key, and the user re-prompts once per restart. This is the slowest UX but the simplest implementation.
+
+n_signer does not know or care which strategy a client uses. The pubkey on the wire is the only thing the signer sees.
+
+### 8.2 Signing each request
+
+For every TCP request, the client:
+
+1. Builds the regular JSON-RPC envelope (`id`, `method`, `params`).
+2. Computes `body_hash = SHA-256(JCS(params))`.
+3. Constructs an auth event with kind 27235, the three required tags, optional `content` label, current `created_at`.
+4. Signs the event with its private key (BIP-340 Schnorr — for nostr_terminal this is the same `nostr_schnorr_sign`-style call it already uses for kind-1 events, just with a different kind and tag set).
+5. Embeds the signed event under an `auth` field in the request.
+6. Sends the framed bytes.
+
+The signing operation is bounded — one Schnorr sign per RPC. Modern hardware does this in microseconds. Implementations should not cache or skip signing; the per-request `created_at` is what makes the nonce defense meaningful.
+
+### 8.3 Reconnect behavior — the bug being fixed
+
+- TCP socket drops mid-session → client reconnects → next RPC carries a fresh auth envelope (different `id`, different `created_at`) signed by the same pubkey.
+- Signer verifies envelope, computes the same `caller_id = "pubkey:<hex>"`, finds the existing approval entry, serves silently. **No prompt.**
+- Signer process restart → policy table empties → next RPC's envelope verifies fine but the policy entry is gone → user re-prompts once per pubkey, picks `[a]`, future requests served silently. **One prompt per signer restart, exactly as for any other caller kind.**
+- Client process restart → if the client persisted its keypair (its own choice), zero prompts. If the client used an ephemeral keypair, one prompt for the new pubkey.
+
+### 8.4 Replay-window awareness
+
+Clients must keep their clock synced within `AUTH_CLOCK_SKEW_SEC` (default 30s). This is normally trivial via NTP. The signer's response on stale-clock errors (`auth_envelope_stale`, code 2016) tells the client to fix its clock; clients should surface this clearly rather than retrying.
+
+### 8.5 No on-disk requirement
+
+The client is **not required** to store anything on disk. Whether it does is the client's policy. n_signer's plan imposes no client-side filesystem state.
+
+## 9. Mermaid: TCP request decision tree
+
+```mermaid
+flowchart TD
+    A[TCP request arrives] --> B[parse JSON, extract auth]
+    B --> C{auth present?}
+    C -- no --> D[reject 2014 auth_envelope_required]
+    C -- yes --> E[validate event structure]
+    E -- bad --> F[reject 2010 auth_envelope_malformed]
+    E -- ok --> G[verify Schnorr signature]
+    G -- bad --> H[reject 2012 auth_signature_invalid]
+    G -- ok --> I{kind == 27235?}
+    I -- no --> J[reject 2013 auth_kind_invalid]
+    I -- yes --> K{tags match request id and method?}
+    K -- no --> L[reject 2015 auth_envelope_mismatch]
+    K -- yes --> M{body hash matches?}
+    M -- no --> N[reject 2011 auth_body_mismatch]
+    M -- yes --> O{within skew window?}
+    O -- no --> P[reject 2016 auth_envelope_stale]
+    O -- yes --> Q{auth.id in nonce cache?}
+    Q -- yes --> R[reject 2017 auth_replay_detected]
+    Q -- no --> S[insert nonce, set caller_id pubkey:hex]
+    S --> T[normal policy_check pipeline]
+    T --> U{verdict}
+    U -- ALLOW --> V[dispatch RPC]
+    U -- DENY --> W[2001 policy_denied]
+    U -- PROMPT --> X[user approves with a, registers caller]
+    X --> V
+```
+
+## 10. Identity primitives compared
+
+| Primitive | Stable across reconnects | Forgeable on TCP/FIPS | Survives client restart | Replay-resistant | n_signer dependency added |
+|---|---|---|---|---|---|
+| `tcp:[addr]:port` (today) | **No** | n/a (it is the address) | n/a | n/a | none |
+| PID claimed in JSON | Yes | **Yes** — any client claims any int | n/a | No | none |
+| 32-byte random bearer token (v1 of this plan) | Yes | Yes if leaked from disk or wire | Only if disk-persisted (rejected) | No | none |
+| **Caller pubkey + Schnorr signature (this plan)** | **Yes** | **No** — signature attests possession | Yes if client retains key (its choice) | Yes (nonce + skew window) | none — `nostr_core_lib` already linked |
+
+The bottom row is the only one that satisfies all four columns and adds zero new transitive dependencies. PID and the v1 token are kept in the table as documentation of why we are not doing them.
+
+PID retains a single legitimate use: **prompt UX context for AF_UNIX**. When the signer can read PID via `SO_PEERCRED`, it is displayed in the approval prompt as `pid=18437 (exe=/usr/local/bin/nostr_terminal)` so the user can `ps -p 18437` and verify. PID is never the policy key.
+
+## 11. Threats addressed and not addressed
+
+### Addressed
+
+- **Connection-churn re-prompting.** The originating bug. One pubkey, one approval.
+- **Same-IP, different-program ambiguity.** Two programs from the same FIPS endpoint hold different keypairs and produce distinct, verified `pubkey:` caller_ids.
+- **Drive-by signing from a process that lacks the privkey.** A network adversary or local-but-unauthorized process cannot forge envelopes. Wire knowledge of the pubkey is non-sensitive; the privkey never leaves the legitimate client's memory.
+- **Replay of captured envelopes.** Bounded by `AUTH_CLOCK_SKEW_SEC` and the in-memory nonce cache.
+- **Tampered request bodies.** `nsigner_body_hash` covers `params`, so a man-in-the-middle who flips a kind-1 request to a kind-30000 request invalidates the signature and is rejected.
+- **Tampered request methods or ids.** Covered by required tags `nsigner_method` and `nsigner_rpc`.
+
+### Not addressed (explicit)
+
+- **A local attacker who reads the client's privkey out of process memory.** They become the registered caller. This is the same threat as today's same-uid trust model and is handled by the OS, not by n_signer.
+- **A network attacker who can both passively observe AND inject AND has compromised the FIPS substrate.** Without TLS at the n_signer layer, transport encryption is FIPS's job. If FIPS confidentiality is broken, the attacker can read envelopes — but they still cannot forge them (no privkey) and they cannot replay them outside the skew window. Confidentiality of `params` is a separate concern from auth.
+- **Signer authenticating to the client.** This plan does the client → signer direction. Signer → client auth is future work; today the client trusts whichever endpoint the operator pointed it at.
+- **Long-term key rotation policy.** Operators rotate by removing the old approval entry (TUI hotkey, future) and prompting the new pubkey. There is no automatic rotation.
+
+## 12. Implementation order (suggested)
+
+Each step is independently testable.
+
+1. **`src/auth_envelope.c` and `tests/test_auth_envelope.c`.** Pure data-structure and crypto wrapper around `nostr_validate_event_structure` + `nostr_verify_event_signature` + tag/body/timestamp/nonce checks. No transport coupling. Test with hand-crafted JSON and fixed test keypairs.
+2. **Nonce cache primitive.** Ring buffer; trivial unit tests for insert / lookup / eviction.
+3. **`caller_identity_t` widening.** Mechanical change across all `NSIGNER_HEADERLESS_DECLS_BEGIN` blocks. Compile-only step; existing tests should still pass.
+4. **Auth gate in `server_handle_one`.** Hook (1) into the request flow at TCP transport. Add the eight new error code responses. Integration test: fire a TCP request without `auth` and confirm rejection with code 2014; fire one with a valid envelope and confirm normal flow.
+5. **`--preapprove caller=pubkey:<hex>` parsing.** Extension to [`parse_preapprove_spec`](../src/policy.c:553).
+6. **`--auth-skew-seconds` flag.** Plumbing.
+7. **Documentation.**
+   - [`documents/SECURITY.md`](../documents/SECURITY.md): replace `tcp_remote (planned)` and `fips (planned)` rows in §11 with the verified-pubkey description; add a section on the auth envelope.
+   - [`documents/CLIENT_IMPLEMENTATION.md`](../documents/CLIENT_IMPLEMENTATION.md): full chapter on the auth envelope, JCS canonicalization rule, the eight error codes, a concrete signing example.
+   - [`documents/FIPS_DEPLOYMENT.md`](../documents/FIPS_DEPLOYMENT.md): note that TCP requests now require auth envelopes; update the deployment checklist; remove the "remote TCP mode only with mandatory TLS + authenticated caller key flow" future-work note since this plan delivers the second half.
+   - [`documents/N_OS_TR_AGENT_CHANGES.md`](../documents/N_OS_TR_AGENT_CHANGES.md): example with `--preapprove caller=pubkey:<hex>`.
+8. **Deprecation handling for `--preapprove caller=tcp:...` on TCP listeners.** Warning at startup; entries effectively dead.
+9. **TUI revocation hotkey.** UX-side, can land later.
+
+## 13. Open questions for review
+
+These are the judgment calls left in v2. None of them block the v2 → implementation move; defaults are stated for each.
+
+1. **Skew window default.** This plan says 30 seconds. Confirm. Tighter (5s) means fewer replay opportunities but more clock-drift errors; looser (120s) the reverse.
+2. **Nonce cache size.** This plan says 1024. With a 30s window that handles ~33 RPS sustained per signer, far above realistic load. Confirm the size is fine.
+3. **Should the auth envelope's `content` field carry a label?** This plan says yes, displayed at prompt as a hint, max 63 bytes UTF-8. Alternative: leave `content` empty and force the operator to recognize the npub. The label is purely UX; the npub is the truth. Default = label allowed, but ignored by policy.
+4. **JCS as canonicalization vs. a simpler rule.** JCS is the right answer (RFC standard, used by NIP-01) but not all client languages have a JCS library. Alternative: define a small subset rule ("sort keys lexicographically, no whitespace, JSON-stringify each value"). Default = JCS; revisit if a target client language lacks support.
+5. **Should AF_UNIX accept an `auth` envelope as an *additional* identity claim?** Today this plan says no — AF_UNIX uses `SO_PEERCRED` and ignores `auth`. Alternative: allow a client over AF_UNIX to ALSO send an envelope and have the signer record both `uid:1000` AND `pubkey:<hex>` as identities for the same caller. Adds complexity for a use case nobody has asked for. Default = AF_UNIX ignores `auth`.
+
+---
+
+## Appendix A — Diff against existing plans and docs
+
+- [`plans/deny_by_default_approvals.md`](deny_by_default_approvals.md): unchanged. The deny-by-default rule, prompt outcomes, on-demand role derivation, and `--preapprove` mechanics all continue. Only the *form* of `caller_id` for one transport changes.
+- [`plans/nsigner.md`](nsigner.md): the future-work item "remote TCP mode only with mandatory TLS + authenticated caller key flow" ([`documents/FIPS_DEPLOYMENT.md:177`](../documents/FIPS_DEPLOYMENT.md:177)) is half answered: the auth side is done; TLS at the n_signer layer remains future work.
+- [`documents/SECURITY.md`](../documents/SECURITY.md):
+  - §11 rows for `tcp_remote` and `fips` move from "planned" to "implemented; identity = caller pubkey verified by Schnorr signature."
+  - New subsection in §5 ("the two checks") inserts an auth check ahead of the approval check, applicable only to TCP transport.
+- [`documents/CLIENT_IMPLEMENTATION.md`](../documents/CLIENT_IMPLEMENTATION.md): new chapter "Authenticating over TCP/URL transport" defining the auth envelope, JCS rule, and error codes 2010–2017.
+- [`documents/N_OS_TR_AGENT_CHANGES.md`](../documents/N_OS_TR_AGENT_CHANGES.md): adds a `--preapprove caller=pubkey:<hex>` example for system services that have a stable identity keypair; notes that `--preapprove caller=tcp:...` is deprecated for TCP listeners.
+
+## Appendix B — Why kind 27235 specifically
+
+NIP-42 already defines kind 22242 for "client authentication to relays" with HTTP-Auth-style semantics. Reusing 22242 verbatim would be wrong because the tag schema (`relay`, `challenge`) is relay-specific. Choosing a fresh kind in the parameterized-replaceable range used for HTTP/RPC auth (27235 is used elsewhere for HTTP request auth in some Nostr ecosystems — verify before locking in) lets us define our own tag schema (`nsigner_rpc`, `nsigner_method`, `nsigner_body_hash`) without colliding with relay-auth conventions.
+
+If 27235 turns out to be already claimed by a NIP we do not want to inherit semantics from, the plan can pick a different kind in the same range. The kind is a constant in [`src/auth_envelope.c`](../src/auth_envelope.c) and changing it is a one-line edit in both signer and client.
+
+## Appendix C — Pseudocode: client signing one request
+
+```c
+/* Pseudocode, illustrative only. */
+cJSON *params = build_params_for_method(method);
+
+/* 1. Compute body hash. */
+char *params_jcs = jcs_canonicalize(params);
+unsigned char body_hash[32];
+nostr_sha256((const unsigned char *)params_jcs, strlen(params_jcs), body_hash);
+char body_hash_hex[65];
+nostr_bytes_to_hex(body_hash, 32, body_hash_hex);
+
+/* 2. Build the auth event JSON. */
+cJSON *auth = cJSON_CreateObject();
+cJSON_AddStringToObject(auth, "pubkey", caller_pubkey_hex);
+cJSON_AddNumberToObject(auth, "created_at", (double)time(NULL));
+cJSON_AddNumberToObject(auth, "kind", 27235);
+
+cJSON *tags = cJSON_CreateArray();
+add_tag(tags, "nsigner_rpc",       request_id);
+add_tag(tags, "nsigner_method",    method);
+add_tag(tags, "nsigner_body_hash", body_hash_hex);
+cJSON_AddItemToObject(auth, "tags", tags);
+
+cJSON_AddStringToObject(auth, "content", optional_label_or_empty);
+
+/* 3. Compute event id (sha256 of canonical event header) and sign. */
+unsigned char event_id[32], sig[64];
+compute_nostr_event_id(auth, event_id);            /* helper from nostr_core_lib usage */
+nostr_schnorr_sign(caller_privkey, event_id, sig);
+
+char id_hex[65], sig_hex[129];
+nostr_bytes_to_hex(event_id, 32, id_hex);
+nostr_bytes_to_hex(sig, 64, sig_hex);
+cJSON_AddStringToObject(auth, "id",  id_hex);
+cJSON_AddStringToObject(auth, "sig", sig_hex);
+
+/* 4. Embed in the request and send. */
+cJSON *root = cJSON_CreateObject();
+cJSON_AddStringToObject(root, "id",     request_id);
+cJSON_AddStringToObject(root, "method", method);
+cJSON_AddItemToObject(root,  "params", params);
+cJSON_AddItemToObject(root,  "auth",   auth);
+send_framed(cJSON_PrintUnformatted(root));
+```
+
+The signer side is the same flow in reverse, replacing `nostr_schnorr_sign` with `nostr_verify_event_signature` on the embedded `auth` event.

plans/docker_runtime_image.md

@@ -0,0 +1,277 @@
+# Plan: Runtime Docker image for n_signer with TCP + auth-envelope onboarding
+
+Status: **draft v1 — for review**
+
+This plan documents a path for new users to download and run [`n_signer`](../README.md) inside a Docker container with minimal friction, while preserving the project's existing security posture (zero filesystem footprint at runtime, mlock'd in-memory secrets, deny-by-default approvals, crash-equals-total-wipe). It complements — and does not replace — the native binary distribution.
+
+The companion work breakdown is tracked as todos in this task; this document captures the rationale and architectural decisions behind those todos.
+
+Related plans and references:
+
+- [`plans/caller_token_identity.md`](caller_token_identity.md) — the auth envelope spec that makes TCP a first-class authenticated transport.
+- [`plans/nip46_bunker_mode.md`](nip46_bunker_mode.md) — deferred relay-based transport that would offer a Docker-friendly future alternative.
+- [`Dockerfile.alpine-musl`](../Dockerfile.alpine-musl) — current build-only Dockerfile that this plan extends.
+- [`build_static.sh`](../build_static.sh) — host-side wrapper around the build image.
+- [`increment_and_push.sh`](../increment_and_push.sh) — existing release flow that this plan extends.
+- [`src/server.c`](../src/server.c) — current transport implementation (`unix`, `stdio`, `qrexec`, `tcp:HOST:PORT`).
+- [`src/auth_envelope.c`](../src/auth_envelope.c) — verifier of NIP-01-shaped `kind:27235` auth envelopes.
+
+---
+
+## 1. Why this plan exists
+
+Today a new user has three realistic on-ramps to `n_signer`:
+
+1. Download the static binary from a release and run it natively.
+2. Clone the repo and rebuild via [`build_static.sh`](../build_static.sh), which itself uses Docker as a build environment but produces a host binary.
+3. Hand-roll a `Dockerfile` and `docker run` invocation around the static binary.
+
+None of those produce a one-command `docker pull` + `docker run` experience. [`Dockerfile.alpine-musl`](../Dockerfile.alpine-musl) ends with `FROM scratch` and copies the binary out — it is a build artifact, not a runnable image. This plan closes that gap.
+
+The Docker path also gives users defense-in-depth that the native path cannot offer: PID-namespace isolation prevents same-user processes on the host from `ptrace`'ing the signer, mount-namespace isolation hides the binary, default seccomp shrinks the kernel attack surface, and `--cap-drop ALL` plus `--security-opt no-new-privileges` constrain a hypothetical compromise of the signer itself. None of this defends against host root, kernel exploits, or side channels — that boundary requires a VM-class isolation like the Qubes path described in [`documents/QUBES_OS.md`](../documents/QUBES_OS.md).
+
+---
+
+## 2. Goals
+
+1. **One-command run.** A new user with Docker installed should be able to `docker pull` and `docker run` to get a working interactive `n_signer` TUI, with no source checkout and no manual binary placement.
+2. **Hardened by default.** The recommended invocation in the documentation must include `--read-only`, `--cap-drop ALL`, `--security-opt no-new-privileges`, resource limits, and `127.0.0.1`-only port publishing. Users who copy-paste the docs land on the safer configuration without having to think.
+3. **TCP is the supported transport for the image.** Out of the four current transports, TCP is the only one that crosses the container/host network-namespace boundary cleanly today, and it is the only one with a working caller-authentication story per [`plans/caller_token_identity.md`](caller_token_identity.md). The image's `ENTRYPOINT` reflects this.
+4. **No new transport code in v1.** This plan uses transports that already exist in [`src/server.c`](../src/server.c). Adding a `unix-path` transport variant for bind-mounted UNIX sockets is a separate plan that this one explicitly does not depend on.
+5. **Preserve the runtime invariants.** Zero filesystem footprint at runtime, mlock'd secrets, crash-equals-total-wipe, and human-attended TUI all carry over. The image runs `--read-only`; no state files; SIGTERM from `docker stop` triggers the same wipe path as Ctrl-C in a terminal.
+6. **Verifiable provenance.** Pulled images must be cryptographically verifiable to a release tag, with an SBOM and vulnerability scan attached as release assets so users can inspect what they are running.
+7. **No regression for the native path.** The static-binary distribution and the `build_static.sh` build flow continue to work unchanged. The Docker image is an *additional* on-ramp, not a replacement.
+
+---
+
+## 3. Non-goals
+
+- **No multi-user, long-running daemon mode.** The TUI-attended, foreground-only design from [`README.md`](../README.md) is preserved. The image is run with `-it`, attached to a terminal. Background `docker run -d` is explicitly unsupported and will be documented as such.
+- **No bundled clients.** The image contains only the signer binary. Clients (browser extension, native apps, examples) ship separately.
+- **No persistent volume.** No mnemonic-on-disk, no policy-on-disk. The signer's "no runtime config or state files" rule from [`README.md`](../README.md) applies unchanged inside the container.
+- **No network exposure beyond loopback by default.** The documented invocation publishes ports to `127.0.0.1` only. LAN/WAN exposure is out of scope and would require a separate threat model plus TLS termination, which is its own plan.
+- **No NIP-46 relay transport.** That remains deferred per [`plans/nip46_bunker_mode.md`](nip46_bunker_mode.md).
+- **No host-UNIX-socket bridging.** Bind-mounting a UNIX socket from the container to the host is appealing for UID-based identity but requires a `--listen unix-path:` mode that does not exist today. Tracked as a follow-up note (todo 20), out of scope here.
+- **No image-internal privilege separation.** The signer runs as a single non-root user inside the container; further compartmentalization (separate uid for TUI vs network handling) is not in scope for v1.
+
+---
+
+## 4. Threat model delta vs. the native binary
+
+The Docker image inherits the same in-process threat model as the native binary (mlock'd secrets, no disk artifacts, deny-by-default approvals). It adds:
+
+| Boundary | Native terminal | Docker image (this plan) |
+|---|---|---|
+| Same-UID host process reads signer memory | Vulnerable to `ptrace`, `/proc/<pid>/mem` | Blocked by PID namespace |
+| Compromised signer escalates on host | Has full UID privileges on host | Constrained by `--cap-drop ALL`, `--security-opt no-new-privileges`, default seccomp |
+| Compromised signer writes persistent files | Can write anywhere UID has access | `--read-only` rootfs blocks writes; no volumes mounted |
+| Core dump leaks key material | Possible if `ulimit` or systemd allows | `--read-only` plus no writable paths means no core file path |
+| Host root reads signer memory | Unconstrained | Still unconstrained — `nsenter`, `docker exec`, host `/proc` all work. **Documented as a non-defense.** |
+| Kernel exploit | Full host compromise | Full host compromise — shared kernel. **Documented as a non-defense.** |
+| Network reachability | Bound by socket file perms or abstract namespace | Bound by Docker port publishing; `127.0.0.1` only by docs |
+| TCP caller identity | Auth envelope (per [`plans/caller_token_identity.md`](caller_token_identity.md)) | Same — unchanged inside the container |
+
+The user-facing security message in [`documents/SECURITY.md`](../documents/SECURITY.md) gets a small subsection (todo 12) calling out exactly this — what Docker buys you and what it does not — so users do not over-trust container isolation.
+
+---
+
+## 5. Image architecture
+
+### 5.1 Multi-stage Dockerfile
+
+Extend [`Dockerfile.alpine-musl`](../Dockerfile.alpine-musl) with a third stage that produces a runnable image. The existing two stages — `builder` and the `FROM scratch AS output` extraction stage — are preserved unchanged so [`build_static.sh`](../build_static.sh) keeps working.
+
+```mermaid
+graph LR
+    A[Stage: builder<br/>alpine:3.19 + toolchain] --> B[Stage: output<br/>FROM scratch<br/>used by build_static.sh]
+    A --> C[Stage: runtime<br/>FROM scratch<br/>ENTRYPOINT nsigner]
+    B -.-> D[host binary<br/>build/nsigner_static_*]
+    C -.-> E[OCI image<br/>nsigner:vX.Y.Z]
+
+    style C fill:#9f9
+    style E fill:#9f9
+```
+
+The runtime stage:
+
+- Starts `FROM scratch` (no shell, no libc, no busybox — the binary is fully static MUSL).
+- Copies in the stripped static binary as `/nsigner`.
+- Sets `ENTRYPOINT ["/nsigner"]` and a default `CMD` of `["--listen", "tcp:0.0.0.0:7777"]`. Users can override CMD to pick another transport, but the ENTRYPOINT remains fixed at the binary.
+- Declares OCI image labels (todo 3) — source URL, version, revision (git SHA), licenses, title, description — sourced from the existing `NSIGNER_VERSION` macro that [`increment_and_push.sh`](../increment_and_push.sh) already maintains.
+- Runs as a non-root UID. Because `FROM scratch` has no `/etc/passwd`, this is done with a numeric UID via `USER 65532`. The static binary has no UID-name dependencies.
+- `EXPOSE 7777` for documentation only (does not affect runtime).
+
+### 5.2 Default `--listen` choice
+
+The image defaults to `--listen tcp:0.0.0.0:7777`. Rationale (todo 15):
+
+- It is the only existing transport that crosses the container netns boundary without `--network=host` (which would defeat the isolation we are running Docker for).
+- It is the only transport with a working caller-authentication story today, via the auth envelope verified in [`src/auth_envelope.c`](../src/auth_envelope.c) and required for TCP per [`src/server.c`](../src/server.c) lines around 1313.
+- `0.0.0.0` inside the container is safe **only** when the host publishes to `127.0.0.1`. The documentation makes this binding explicit and warns against `-p 7777:7777` (which publishes to all host interfaces). Todo 16 covers this in detail.
+- Users who want stdio (one-shot) or qrexec (Qubes-specific) override `CMD` themselves; the default targets the dominant Docker-on-laptop case.
+
+### 5.3 Image size and layers
+
+Static MUSL binary, stripped, is roughly single-digit MB. The runtime image will be that plus the OCI metadata — well under 10 MB. `docker pull` is a few seconds on any reasonable connection. This is documented as a property, not just a coincidence, because it directly supports the "easy for new users" goal.
+
+---
+
+## 6. Build, tag, and publish flow
+
+```mermaid
+graph LR
+    Dev[Developer<br/>./increment_and_push.sh -r] --> Bump[Bump version macros]
+    Bump --> Tag[git tag vX.Y.Z]
+    Tag --> Build[Build static binaries<br/>x86_64 + arm64]
+    Build --> Test[Run make test inside builder]
+    Test --> Img[Build runtime image<br/>buildx multiarch]
+    Img --> Sbom[Generate SBOM + vuln scan]
+    Sbom --> Sign[cosign sign image]
+    Sign --> Push[Push image and assets<br/>to registry]
+    Push --> Release[Create Gitea release<br/>with binary, sbom, image digest, verify cmd]
+```
+
+### 6.1 Registry choice
+
+Decision pending (todo 4). Three viable destinations:
+
+1. **The existing Gitea registry at `git.laantungir.net`.** Aligns with the existing release flow that already uses `~/.gitea_token`. Self-hosted, under project control. Downside: less familiar to new users; they may need to log in to pull.
+2. **GitHub Container Registry (GHCR).** Free, public, well-known, integrates with cosign keyless signing using GitHub OIDC. Requires a GitHub mirror.
+3. **Docker Hub.** Most familiar to new users. Rate limits on anonymous pulls. Requires a Docker Hub account and token.
+
+The plan recommends GHCR as primary because keyless cosign signing dramatically simplifies the trust story for new users (`cosign verify ghcr.io/...` with no key management). The Gitea registry is a viable alternative if the project prefers to stay self-hosted; in that case, key-based cosign signing replaces keyless. Either way, the choice is documented up front so users know where to pull from.
+
+### 6.2 Multi-arch
+
+Built via `docker buildx build --platform linux/amd64,linux/arm64`. The existing builder stage already handles both architectures (it picks `libnostr_core_x64.a` vs `libnostr_core_arm64.a` based on `uname -m`). A `Makefile` target (todo 2) wraps this so the developer command is `make docker-image-multiarch`.
+
+### 6.3 Tags
+
+- `vX.Y.Z` — immutable, matches git tag and binary release.
+- `latest` — moves to newest stable release.
+- `vX` and `vX.Y` — moving tags for users who want major/minor pinning.
+
+All tags are signed; `latest` is signed at each release.
+
+### 6.4 Provenance
+
+Every release attaches:
+
+- Image digest (`sha256:...`) in release notes.
+- `cosign verify` command line as a copy-pasteable block.
+- SBOM in SPDX or CycloneDX format (syft) as a release asset and as an OCI attestation attached to the image.
+- Vulnerability scan output (grype or trivy) as a release asset.
+
+This makes "is the image I pulled the one the project published?" a one-command answer. Todos 6 and 7 cover this.
+
+### 6.5 Hooks into the existing release script
+
+[`increment_and_push.sh`](../increment_and_push.sh) currently:
+
+1. Bumps the version macros in `src/main.h` or `src/main.c`.
+2. Tags the commit.
+3. Builds x86_64 and arm64 static binaries.
+4. Verifies `--version` of each binary matches the new tag.
+5. Creates a Gitea release and uploads the binaries and a source tarball.
+
+The image flow plugs in between steps 4 and 5 (todo 5):
+
+5a. Build the runtime image for both architectures via buildx.
+5b. Generate SBOM and vuln scan.
+5c. Sign with cosign.
+5d. Push the image and signatures to the chosen registry.
+5e. Capture the resulting digest for the release notes.
+
+Each of these steps is gated on a credential being present, mirroring the existing `~/.gitea_token` check. A developer without registry credentials still gets a successful binary release; the image steps emit warnings and skip. This keeps the local release flow usable in offline or partial-credential setups.
+
+### 6.6 CI integration
+
+A CI smoke test (todo 13) boots the just-built runtime image with the default `--listen tcp:0.0.0.0:7777`, drives a single `get_public_key` request from a host client over the published port, and asserts a clean shutdown. This catches regressions where the binary builds but cannot actually serve TCP from inside a container — for example, a future code change that defaults to abstract sockets in a way that breaks netns separation.
+
+The existing `make test` suite is also run inside the builder stage (todo 14) before the artifact is extracted, so we have a tested-then-shipped guarantee on the binary that ends up in the image.
+
+---
+
+## 7. New-user runbook (target end-state)
+
+This is the experience the plan is optimizing for. After the work is done, the [`documents/DOCKER.md`](../documents/DOCKER.md) (todo 8) opens with effectively this:
+
+```bash
+# 1. Verify the image you are about to run
+cosign verify ghcr.io/laantungir/nsigner:v0.X.Y \
+  --certificate-identity-regexp 'https://github.com/laantungir/n_signer' \
+  --certificate-oidc-issuer https://token.actions.githubusercontent.com
+
+# 2. Run with hardened defaults
+docker run -it --rm \
+  --read-only \
+  --cap-drop ALL \
+  --security-opt no-new-privileges \
+  --pids-limit 64 \
+  --memory 128m \
+  -p 127.0.0.1:7777:7777 \
+  ghcr.io/laantungir/nsigner:v0.X.Y
+```
+
+The TUI then comes up exactly as it does for the native binary — mnemonic prompt, role table, status display, approval prompts. From the user's perspective, the only differences are the longer command line and the fact that pressing Ctrl-C now also stops the container.
+
+A second documentation block (todo 9) walks through writing a TCP client that builds a `kind:27235` auth envelope per [`plans/caller_token_identity.md`](caller_token_identity.md), signs it with BIP-340 Schnorr, and gets approved exactly once at the TUI. A worked example client is added to [`examples/`](../examples) (todo 10) so users have a copy-pasteable starting point that they can run on the host against the containerized signer.
+
+---
+
+## 8. Risks and decisions
+
+### 8.1 TCP-only is a real limitation
+
+UID-based identity is preserved on AF_UNIX abstract sockets, which is a strong primitive in the native deployment. In Docker, that primitive is gone — abstract sockets do not cross netns. This plan accepts that and shifts to pubkey-based identity via the auth envelope. The trade-off is documented; users who specifically want UID-based identity stay on the native binary, or wait for the future `unix-path` transport plan (todo 20) that would let them bind-mount a pathname socket and recover `SO_PEERCRED.uid`. UID identity inside the container is also affected by Docker user-namespace remapping, which is another reason this plan does not pretend AF_UNIX inside a container is equivalent to AF_UNIX on the host.
+
+### 8.2 `0.0.0.0` inside the container is unforgiving of misconfiguration
+
+If a user copies the image's default `CMD` but writes `-p 7777:7777` (forgetting the `127.0.0.1:` prefix), they expose the signer to any host on the network. This is documented prominently (todo 16) with the explicit warning. We considered defaulting the CMD to `tcp:127.0.0.1:7777`, but that breaks Docker's port-publishing model — the host-side `127.0.0.1:7777` proxy needs to talk to the container's network interface, which is not loopback. So the safer-looking default is actually broken. The chosen approach (default `0.0.0.0` inside, document loopback publishing on the host) is the only one that works with Docker's networking semantics, but it requires that warning.
+
+### 8.3 TUI under `docker run -it` may have edge cases
+
+The signer's TUI uses raw terminal input for keystroke approvals, ANSI status redraws, and signal-driven shutdown. Most of this works under `docker run -it` but the plan reserves a verification step (todo 19) to confirm:
+
+- `a` / `y` / `n` / `q` / `l` keystrokes deliver the same response as on a native terminal.
+- ANSI redraws do not get garbled by Docker's TTY layer.
+- `docker stop` (which sends SIGTERM, then SIGKILL after grace) triggers the same total-state-wipe path as Ctrl-C, including mnemonic zeroization.
+- `docker kill` (SIGKILL only) leaves no recoverable state — by the existing crash-equals-wipe property, this should already hold, but the plan explicitly tests it.
+
+Any deviation discovered is documented as a caveat in [`documents/DOCKER.md`](../documents/DOCKER.md), not silently worked around.
+
+### 8.4 Host root is not blocked
+
+The plan documents this as a non-defense. Users whose threat model includes "another user on the same host has root" should not assume Docker isolates against that. They should run on a system where they trust root, or move to a Qubes-style VM compartment as documented in [`documents/QUBES_OS.md`](../documents/QUBES_OS.md). This is not a flaw in the plan; it is a property of containers that is easy to misunderstand and therefore worth stating up front.
+
+### 8.5 Image sprawl across registries
+
+If both Gitea and GHCR end up hosting the image, users may pull the wrong one or skip signature verification because "the other registry's image is the same anyway." The decision in §6.1 (one primary registry) is made specifically to avoid this. A secondary mirror is acceptable only if it carries the same digests and the same cosign signatures, and the documentation makes the mirror status explicit.
+
+---
+
+## 9. Out of scope, explicitly
+
+Listed so the plan's scope is clear:
+
+- TLS termination for TCP (a reverse-proxy-in-container pattern).
+- Remote signing (binding TCP to non-loopback). Both require a separate threat model and are deferred.
+- A `--listen unix-path:` transport that would let Docker users bind-mount a pathname socket. Tracked as todo 20 for a follow-up plan.
+- A NIP-46 relay transport. Deferred per [`plans/nip46_bunker_mode.md`](nip46_bunker_mode.md).
+- Reproducible builds in the strict bit-for-bit sense. The static-binary build is already close to deterministic, but full reproducibility (matching digests across rebuilds at a given tag) is its own engineering problem and is not promised here.
+- Distro packages (deb, rpm, Homebrew). The native binary remains a release asset; OS-native packaging is its own track.
+
+---
+
+## 10. Acceptance criteria
+
+The plan is considered delivered when **all** of the following are true:
+
+1. A new user with only Docker installed can pull and run the image with one `docker run` command from [`documents/DOCKER.md`](../documents/DOCKER.md) and see the same TUI they would see from the native binary.
+2. `cosign verify` against the published image passes for the chosen registry, and the verification command is in the release notes for that tag.
+3. SBOM and vulnerability scan output are attached to the release.
+4. Pressing Ctrl-C in the attached terminal, and `docker stop` from another shell, both result in the signer process exiting cleanly with the existing zeroization path having run. No leftover state on the container's writable layer (which is `--read-only` anyway).
+5. A TCP client running on the host, using the example added in todo 10, can complete one `get_public_key` round trip after a single `[a]` approval at the TUI, and a second request from the same client pubkey is served silently.
+6. The CI smoke test (todo 13) is green on every PR that touches `Dockerfile.alpine-musl`, the runtime stage, or `src/server.c`.
+7. [`README.md`](../README.md) links to [`documents/DOCKER.md`](../documents/DOCKER.md) from a "Run in Docker" quickstart section, and [`documents/SECURITY.md`](../documents/SECURITY.md) carries the Docker-specific subsection from todo 12.
+8. The native binary distribution and `make static` flow produce identical artifacts to before this plan landed. No regression.

plans/nip46_bunker_mode.md

@@ -0,0 +1,98 @@
+# Plan: Deferred NIP-46 bunker transport mode
+
+Status: **deferred (design only, not in current implementation scope)**
+
+This document records a future transport mode where `n_signer` can operate as a NIP-46-compatible bunker over relays, while keeping the current local/TCP framed JSON-RPC path intact.
+
+Current implementation priority remains [`plans/caller_token_identity.md`](caller_token_identity.md): required per-request caller authentication for TCP/URL using signed auth envelopes and existing `n_signer` request flow.
+
+---
+
+## 1. Why this is deferred
+
+NIP-46 adds more than caller authentication:
+
+- Relay session lifecycle and routing
+- NIP-44 encrypted request/response payloads
+- `connect` ceremony and secret verification
+- Signer service identity (`remote-signer-pubkey`) management
+- Compatibility behavior for `nostrconnect://` and `bunker://`
+
+That is a separate subsystem from the immediate bugfix (stable, authenticated caller identity over TCP reconnects). Combining both now would increase risk and delay rollout.
+
+---
+
+## 2. Future objective
+
+Add an optional mode (example: `--listen nip46`) that accepts NIP-46 `kind:24133` requests and returns NIP-46 `kind:24133` responses as defined in [`resources/nips/46.md`](../resources/nips/46.md).
+
+This mode should:
+
+1. Authenticate client requests using NIP-46 client keypairs and encrypted content.
+2. Map NIP-46 caller identity to the same deny-by-default approval model already used by current transports.
+3. Reuse existing dispatcher/enforcement/policy machinery after transport decoding.
+
+---
+
+## 3. Compatibility stance (future)
+
+- Keep current framed JSON-RPC transports (`AF_UNIX`, `qrexec`, `tcp`) as first-class for local deployments.
+- Add NIP-46 as **additional** transport, not replacement.
+- Shared internal core: once a request is decoded into `(caller_id, method, params, selector)`, the same policy and enforcement pipeline runs.
+
+---
+
+## 4. Planned phases
+
+### Phase A — Transport shell
+
+- Add `nip46` listen mode and relay I/O loop.
+- Parse and validate incoming `kind:24133` envelope.
+- Decrypt NIP-44 payload and extract JSON-RPC-like `method` + `params`.
+
+### Phase B — Identity + approval binding
+
+- Derive caller identity from NIP-46 `client-pubkey`.
+- Represent as `caller_id = pubkey:<hex>` to align with the current TCP auth direction in [`plans/caller_token_identity.md`](caller_token_identity.md).
+- Route to existing policy checks and prompt behavior.
+
+### Phase C — Response path
+
+- Convert dispatcher results into NIP-46 response payloads.
+- Encrypt via NIP-44 and emit `kind:24133` response event.
+- Preserve request `id` correlation and error mapping.
+
+### Phase D — Connect / secret / perms polish
+
+- Implement full `connect` handshake semantics from [`resources/nips/46.md`](../resources/nips/46.md:100).
+- Validate optional secret behavior.
+- Support requested permissions metadata and signer-side policy translation.
+
+### Phase E — Operational hardening
+
+- Relay switching behavior (`switch_relays`), lifecycle recovery.
+- Rate limits and replay protections specific to relay transport.
+- Audit/event logs for NIP-46 connections and requests.
+
+---
+
+## 5. Open design questions (for later)
+
+1. Should NIP-46 mode require a dedicated signer identity key, or may it reuse the user signing identity?
+2. How should `connect` permissions map to `n_signer` role/selector approvals?
+3. Should NIP-46 callers and TCP-auth callers share the same `pubkey:<hex>` approval namespace by default?
+4. Do we support both relay-initiated and direct-client initiation flows from day one?
+5. What minimum relay trust assumptions are required in `documents/SECURITY.md`?
+
+---
+
+## 6. Out of scope for current code work
+
+The current implementation task does **not** include:
+
+- Adding relay networking
+- NIP-44 tunnel encryption for requests
+- NIP-46 `connect` handshake
+- `nostrconnect://` URI flow
+
+Those remain deferred to this plan.

src/auth_envelope.c

@@ -0,0 +1,409 @@
+#define _GNU_SOURCE
+
+#include "auth_envelope.h"
+
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include <cJSON.h>
+#include <nostr_core/nip001.h>
+#include <nostr_core/utils.h>
+
+static int set_error(int *out_code,
+                     const char **out_message,
+                     int code,
+                     const char *message) {
+    if (out_code != NULL) {
+        *out_code = code;
+    }
+    if (out_message != NULL) {
+        *out_message = message;
+    }
+    return -1;
+}
+
+void auth_nonce_cache_init(auth_nonce_cache_t *cache) {
+    if (cache == NULL) {
+        return;
+    }
+    memset(cache, 0, sizeof(*cache));
+}
+
+static int auth_nonce_cache_contains(const auth_nonce_cache_t *cache, const uint8_t id[32]) {
+    int i;
+
+    if (cache == NULL || id == NULL) {
+        return 0;
+    }
+
+    for (i = 0; i < cache->count; ++i) {
+        if (memcmp(cache->ids[i], id, 32) == 0) {
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
+static void auth_nonce_cache_insert(auth_nonce_cache_t *cache, const uint8_t id[32]) {
+    if (cache == NULL || id == NULL) {
+        return;
+    }
+
+    if (cache->count < AUTH_NONCE_CACHE_SIZE) {
+        memcpy(cache->ids[cache->count], id, 32);
+        cache->count++;
+        return;
+    }
+
+    memcpy(cache->ids[cache->next], id, 32);
+    cache->next = (cache->next + 1) % AUTH_NONCE_CACHE_SIZE;
+}
+
+static int json_item_to_compact_string(const cJSON *item, char *out, size_t out_sz) {
+    char *printed;
+
+    if (out == NULL || out_sz == 0 || item == NULL) {
+        return -1;
+    }
+
+    if (cJSON_IsString(item) && item->valuestring != NULL) {
+        strncpy(out, item->valuestring, out_sz - 1);
+        out[out_sz - 1] = '\0';
+        return 0;
+    }
+
+    printed = cJSON_PrintUnformatted((cJSON *)item);
+    if (printed == NULL) {
+        return -1;
+    }
+
+    strncpy(out, printed, out_sz - 1);
+    out[out_sz - 1] = '\0';
+    free(printed);
+    return 0;
+}
+
+static int compute_hash_hex_for_json_item(const cJSON *item, char *out_hex, size_t out_hex_sz) {
+    unsigned char hash[32];
+    char *compact = NULL;
+
+    if (out_hex == NULL || out_hex_sz < 65) {
+        return -1;
+    }
+
+    if (item == NULL) {
+        compact = strdup("null");
+    } else {
+        compact = cJSON_PrintUnformatted((cJSON *)item);
+    }
+
+    if (compact == NULL) {
+        return -1;
+    }
+
+    if (nostr_sha256((const unsigned char *)compact, strlen(compact), hash) != 0) {
+        free(compact);
+        return -1;
+    }
+
+    nostr_bytes_to_hex(hash, sizeof(hash), out_hex);
+    out_hex[64] = '\0';
+    free(compact);
+    return 0;
+}
+
+static int compute_params_hash_hex(cJSON *root, char *out_hex, size_t out_hex_sz) {
+    cJSON *params = cJSON_GetObjectItemCaseSensitive(root, "params");
+    return compute_hash_hex_for_json_item(params, out_hex, out_hex_sz);
+}
+
+static cJSON *find_tag_value(cJSON *tags, const char *name) {
+    int i;
+
+    if (!cJSON_IsArray(tags) || name == NULL) {
+        return NULL;
+    }
+
+    for (i = 0; i < cJSON_GetArraySize(tags); ++i) {
+        cJSON *tag = cJSON_GetArrayItem(tags, i);
+        cJSON *tag_name;
+        cJSON *tag_value;
+
+        if (!cJSON_IsArray(tag) || cJSON_GetArraySize(tag) < 2) {
+            continue;
+        }
+
+        tag_name = cJSON_GetArrayItem(tag, 0);
+        tag_value = cJSON_GetArrayItem(tag, 1);
+        if (!cJSON_IsString(tag_name) || tag_name->valuestring == NULL) {
+            continue;
+        }
+        if (strcmp(tag_name->valuestring, name) != 0) {
+            continue;
+        }
+
+        return tag_value;
+    }
+
+    return NULL;
+}
+
+static cJSON *build_tag_pair(const char *name, const char *value) {
+    cJSON *pair;
+
+    if (name == NULL || value == NULL) {
+        return NULL;
+    }
+
+    pair = cJSON_CreateArray();
+    if (pair == NULL) {
+        return NULL;
+    }
+
+    cJSON_AddItemToArray(pair, cJSON_CreateString(name));
+    cJSON_AddItemToArray(pair, cJSON_CreateString(value));
+    return pair;
+}
+
+int auth_envelope_build_for_request(const char *request_id,
+                                    const char *method,
+                                    const cJSON *params,
+                                    const unsigned char privkey[32],
+                                    const char *label,
+                                    time_t created_at,
+                                    cJSON **out_auth) {
+    cJSON *tags = NULL;
+    cJSON *auth = NULL;
+    char body_hash_hex[65];
+
+    if (out_auth == NULL || request_id == NULL || method == NULL ||
+        privkey == NULL || request_id[0] == '\0' || method[0] == '\0') {
+        return -1;
+    }
+
+    *out_auth = NULL;
+
+    if (compute_hash_hex_for_json_item(params, body_hash_hex, sizeof(body_hash_hex)) != 0) {
+        return -1;
+    }
+
+    tags = cJSON_CreateArray();
+    if (tags == NULL) {
+        return -1;
+    }
+
+    cJSON_AddItemToArray(tags, build_tag_pair("nsigner_rpc", request_id));
+    cJSON_AddItemToArray(tags, build_tag_pair("nsigner_method", method));
+    cJSON_AddItemToArray(tags, build_tag_pair("nsigner_body_hash", body_hash_hex));
+
+    if (created_at <= 0) {
+        created_at = time(NULL);
+    }
+
+    auth = nostr_create_and_sign_event(AUTH_EVENT_KIND,
+                                       (label != NULL) ? label : "",
+                                       tags,
+                                       privkey,
+                                       created_at);
+
+    if (auth == NULL) {
+        cJSON_Delete(tags);
+        return -1;
+    }
+
+    *out_auth = auth;
+    return 0;
+}
+
+int auth_envelope_verify_request(const char *request_json,
+                                 auth_nonce_cache_t *cache,
+                                 int skew_seconds,
+                                 char *out_pubkey_hex,
+                                 size_t out_pubkey_hex_sz,
+                                 char *out_label,
+                                 size_t out_label_sz,
+                                 int *out_error_code,
+                                 const char **out_error_message) {
+    cJSON *root = NULL;
+    cJSON *auth = NULL;
+    cJSON *method_item;
+    cJSON *id_item;
+    cJSON *kind_item;
+    cJSON *created_item;
+    cJSON *pubkey_item;
+    cJSON *content_item;
+    cJSON *id_hex_item;
+    cJSON *tags_item;
+    cJSON *tag_rpc;
+    cJSON *tag_method;
+    cJSON *tag_body_hash;
+    char request_id[128];
+    char body_hash_hex[65];
+    uint8_t nonce_bytes[32];
+    time_t now;
+    long long created;
+
+    if (out_error_code != NULL) {
+        *out_error_code = 0;
+    }
+    if (out_error_message != NULL) {
+        *out_error_message = NULL;
+    }
+
+    if (out_pubkey_hex == NULL || out_pubkey_hex_sz < 65 ||
+        out_label == NULL || out_label_sz == 0 ||
+        request_json == NULL || cache == NULL) {
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_ENVELOPE_MALFORMED,
+                         "auth_envelope_malformed");
+    }
+
+    out_pubkey_hex[0] = '\0';
+    out_label[0] = '\0';
+
+    root = cJSON_Parse(request_json);
+    if (root == NULL) {
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_ENVELOPE_MALFORMED,
+                         "auth_envelope_malformed");
+    }
+
+    method_item = cJSON_GetObjectItemCaseSensitive(root, "method");
+    id_item = cJSON_GetObjectItemCaseSensitive(root, "id");
+    if (!cJSON_IsString(method_item) || method_item->valuestring == NULL ||
+        json_item_to_compact_string(id_item, request_id, sizeof(request_id)) != 0) {
+        cJSON_Delete(root);
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_ENVELOPE_MALFORMED,
+                         "auth_envelope_malformed");
+    }
+
+    auth = cJSON_GetObjectItemCaseSensitive(root, "auth");
+    if (!cJSON_IsObject(auth)) {
+        cJSON_Delete(root);
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_ENVELOPE_REQUIRED,
+                         "auth_envelope_required");
+    }
+
+    if (nostr_validate_event_structure(auth) != 0) {
+        cJSON_Delete(root);
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_ENVELOPE_MALFORMED,
+                         "auth_envelope_malformed");
+    }
+
+    if (nostr_verify_event_signature(auth) != 0) {
+        cJSON_Delete(root);
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_SIGNATURE_INVALID,
+                         "auth_signature_invalid");
+    }
+
+    kind_item = cJSON_GetObjectItemCaseSensitive(auth, "kind");
+    if (!cJSON_IsNumber(kind_item) || kind_item->valueint != AUTH_EVENT_KIND) {
+        cJSON_Delete(root);
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_KIND_INVALID,
+                         "auth_kind_invalid");
+    }
+
+    tags_item = cJSON_GetObjectItemCaseSensitive(auth, "tags");
+    tag_rpc = find_tag_value(tags_item, "nsigner_rpc");
+    tag_method = find_tag_value(tags_item, "nsigner_method");
+    tag_body_hash = find_tag_value(tags_item, "nsigner_body_hash");
+    if (!cJSON_IsString(tag_rpc) || tag_rpc->valuestring == NULL ||
+        !cJSON_IsString(tag_method) || tag_method->valuestring == NULL ||
+        !cJSON_IsString(tag_body_hash) || tag_body_hash->valuestring == NULL) {
+        cJSON_Delete(root);
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_ENVELOPE_MALFORMED,
+                         "auth_envelope_malformed");
+    }
+
+    if (strcmp(tag_rpc->valuestring, request_id) != 0 ||
+        strcmp(tag_method->valuestring, method_item->valuestring) != 0) {
+        cJSON_Delete(root);
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_ENVELOPE_MISMATCH,
+                         "auth_envelope_mismatch");
+    }
+
+    if (compute_params_hash_hex(root, body_hash_hex, sizeof(body_hash_hex)) != 0 ||
+        strcasecmp(tag_body_hash->valuestring, body_hash_hex) != 0) {
+        cJSON_Delete(root);
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_BODY_MISMATCH,
+                         "auth_body_mismatch");
+    }
+
+    created_item = cJSON_GetObjectItemCaseSensitive(auth, "created_at");
+    if (!cJSON_IsNumber(created_item)) {
+        cJSON_Delete(root);
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_ENVELOPE_MALFORMED,
+                         "auth_envelope_malformed");
+    }
+
+    if (skew_seconds <= 0) {
+        skew_seconds = AUTH_DEFAULT_SKEW_SECONDS;
+    }
+
+    now = time(NULL);
+    created = (long long)created_item->valuedouble;
+    if (llabs((long long)now - created) > (long long)skew_seconds) {
+        cJSON_Delete(root);
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_ENVELOPE_STALE,
+                         "auth_envelope_stale");
+    }
+
+    id_hex_item = cJSON_GetObjectItemCaseSensitive(auth, "id");
+    if (!cJSON_IsString(id_hex_item) || id_hex_item->valuestring == NULL ||
+        strlen(id_hex_item->valuestring) != 64 ||
+        nostr_hex_to_bytes(id_hex_item->valuestring, nonce_bytes, sizeof(nonce_bytes)) != 0) {
+        cJSON_Delete(root);
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_ENVELOPE_MALFORMED,
+                         "auth_envelope_malformed");
+    }
+
+    if (auth_nonce_cache_contains(cache, nonce_bytes)) {
+        cJSON_Delete(root);
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_REPLAY_DETECTED,
+                         "auth_replay_detected");
+    }
+    auth_nonce_cache_insert(cache, nonce_bytes);
+
+    pubkey_item = cJSON_GetObjectItemCaseSensitive(auth, "pubkey");
+    if (!cJSON_IsString(pubkey_item) || pubkey_item->valuestring == NULL ||
+        strlen(pubkey_item->valuestring) != 64) {
+        cJSON_Delete(root);
+        return set_error(out_error_code, out_error_message,
+                         AUTH_ERR_ENVELOPE_MALFORMED,
+                         "auth_envelope_malformed");
+    }
+
+    strncpy(out_pubkey_hex, pubkey_item->valuestring, out_pubkey_hex_sz - 1);
+    out_pubkey_hex[out_pubkey_hex_sz - 1] = '\0';
+
+    content_item = cJSON_GetObjectItemCaseSensitive(auth, "content");
+    if (cJSON_IsString(content_item) && content_item->valuestring != NULL) {
+        size_t i;
+        for (i = 0; content_item->valuestring[i] != '\0' && i + 1 < out_label_sz; ++i) {
+            unsigned char ch = (unsigned char)content_item->valuestring[i];
+            out_label[i] = (char)((isprint(ch) && ch != '\n' && ch != '\r' && ch != '\t') ? ch : ' ');
+        }
+        out_label[i] = '\0';
+    } else {
+        out_label[0] = '\0';
+    }
+
+    cJSON_Delete(root);
+    return 0;
+}

src/auth_envelope.h

@@ -0,0 +1,49 @@
+#ifndef NSIGNER_AUTH_ENVELOPE_H
+#define NSIGNER_AUTH_ENVELOPE_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <time.h>
+
+#include <cJSON.h>
+
+#define AUTH_NONCE_CACHE_SIZE 1024
+#define AUTH_DEFAULT_SKEW_SECONDS 30
+#define AUTH_EVENT_KIND 27235
+
+#define AUTH_ERR_ENVELOPE_MALFORMED 2010
+#define AUTH_ERR_BODY_MISMATCH 2011
+#define AUTH_ERR_SIGNATURE_INVALID 2012
+#define AUTH_ERR_KIND_INVALID 2013
+#define AUTH_ERR_ENVELOPE_REQUIRED 2014
+#define AUTH_ERR_ENVELOPE_MISMATCH 2015
+#define AUTH_ERR_ENVELOPE_STALE 2016
+#define AUTH_ERR_REPLAY_DETECTED 2017
+
+typedef struct {
+    uint8_t ids[AUTH_NONCE_CACHE_SIZE][32];
+    int count;
+    int next;
+} auth_nonce_cache_t;
+
+void auth_nonce_cache_init(auth_nonce_cache_t *cache);
+
+int auth_envelope_verify_request(const char *request_json,
+                                 auth_nonce_cache_t *cache,
+                                 int skew_seconds,
+                                 char *out_pubkey_hex,
+                                 size_t out_pubkey_hex_sz,
+                                 char *out_label,
+                                 size_t out_label_sz,
+                                 int *out_error_code,
+                                 const char **out_error_message);
+
+int auth_envelope_build_for_request(const char *request_id,
+                                    const char *method,
+                                    const cJSON *params,
+                                    const unsigned char privkey[32],
+                                    const char *label,
+                                    time_t created_at,
+                                    cJSON **out_auth);
+
+#endif

src/dispatcher.c

@@ -229,7 +229,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -396,7 +396,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

src/enforcement.c

@@ -229,7 +229,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -384,7 +384,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

src/key_store.c

@@ -231,7 +231,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -389,7 +389,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

src/main.c

@@ -234,7 +234,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -395,13 +395,17 @@ char *dispatcher_handle_request(dispatcher_ctx_t *ctx, const char *json_request)
 #define NSIGNER_LISTEN_QREXEC 2
 #define NSIGNER_LISTEN_TCP    3
 
+#define NSIGNER_AUTH_OFF      0
+#define NSIGNER_AUTH_OPTIONAL 1
+#define NSIGNER_AUTH_REQUIRED 2
+
 /* Caller identity */
 typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
     int kind;
-    char caller_id[64];     /* "uid:<n>" or "qubes:<vm>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];     /* "uid:<n>" or "qubes:<vm>" */
     char source_qube[64];
 } caller_identity_t;
 
@@ -416,12 +420,16 @@ typedef struct {
     dispatcher_ctx_t *dispatcher;
     policy_table_t *policy;
     int socket_name_explicit;
+    int auth_mode;
+    int auth_skew_seconds;
 } server_ctx_t;
 
 /* Initialize server context. socket_name is the abstract namespace name (e.g. "nsigner").
  * socket_name_explicit should be non-zero when provided via --socket-name override. */
 void server_init(server_ctx_t *ctx, const char *socket_name, int socket_name_explicit,
                  int listen_mode,
+                 int auth_mode,
+                 int auth_skew_seconds,
                  dispatcher_ctx_t *dispatcher, policy_table_t *policy);
 
 /* Start listening. Returns 0 on success, -1 on error. */
@@ -468,8 +476,8 @@ int socket_name_random(char *out, size_t out_len);
 /* Version information (auto-updated by build/version tooling) */
 #define NSIGNER_VERSION_MAJOR 0
 #define NSIGNER_VERSION_MINOR 0
-#define NSIGNER_VERSION_PATCH 16
-#define NSIGNER_VERSION "v0.0.16"
+#define NSIGNER_VERSION_PATCH 25
+#define NSIGNER_VERSION "v0.0.25"
 
 
 /* NSIGNER_HEADERLESS_DECLS_END */
@@ -477,6 +485,7 @@ int socket_name_random(char *out, size_t out_len);
 int transport_send_framed(int fd, const char *payload);
 int transport_recv_framed(int fd, char **out_payload, size_t max_size);
 
+#include "auth_envelope.h"
 #include <nostr_core/nostr_common.h>
 
 #include <arpa/inet.h>
@@ -565,8 +574,9 @@ static int connect_abstract_socket(const char *name) {
 static void print_usage(const char *program_name) {
     printf("nsigner - single-binary signer program\n");
     printf("Usage:\n");
-    printf("  %s [--socket-name|--name|-n <name>] [--listen <unix|stdio|qrexec|tcp:HOST:PORT>]\n", program_name);
-    printf("                                           [--preapprove <SPEC>]...\n");
+    printf("  %s [--socket-name|--name|-n <name>] [--listen|-l <unix|stdio|qrexec|tcp:HOST:PORT>]\n", program_name);
+    printf("                                           [--preapprove|-p <SPEC>]... [--auth|-a <off|optional|required>]\n");
+    printf("                                           [--allow-all|-A]\n");
     printf("                                           Run signer server (unix mode has TUI)\n");
     printf("  %s [--socket-name|--name|-n <name>] client '<json>' Send JSON-RPC request\n", program_name);
     printf("  %s [--socket-name|--name|-n <name>] client -        Read JSON-RPC request from stdin\n", program_name);
@@ -574,8 +584,12 @@ static void print_usage(const char *program_name) {
     printf("  %s --help\n", program_name);
     printf("  %s --version\n", program_name);
     printf("\nOptions:\n");
-    printf("  --preapprove SPEC   Pre-approve a caller for a role (repeatable)\n");
+    printf("  --listen, -l MODE   Listener transport: unix|stdio|qrexec|tcp:HOST:PORT\n");
+    printf("  --preapprove, -p SPEC\n");
+    printf("                      Pre-approve a caller for a role (repeatable)\n");
     printf("                      SPEC: caller=<id>,role=<name> or caller=<id>,nostr_index=<n>\n");
+    printf("  --auth, -a MODE     Auth envelope policy per listener: off|optional|required\n");
+    printf("  --allow-all, -A     Allow all policy prompts for this server session\n");
 }
 
 static int extract_nsigner_socket_from_proc_line(const char *line,
@@ -1018,6 +1032,9 @@ int main(int argc, char *argv[]) {
     int argi = 1;
     const char *preapprove_specs[POLICY_MAX_ENTRIES];
     int preapprove_count = 0;
+    int auth_mode = NSIGNER_AUTH_OFF;
+    int auth_skew_seconds = AUTH_DEFAULT_SKEW_SECONDS;
+    int allow_all = 0;
 
     while (argi < argc) {
         if (strcmp(argv[argi], "--socket-name") == 0 ||
@@ -1032,7 +1049,7 @@ int main(int argc, char *argv[]) {
             argi += 2;
             continue;
         }
-        if (strcmp(argv[argi], "--listen") == 0) {
+        if (strcmp(argv[argi], "--listen") == 0 || strcmp(argv[argi], "-l") == 0) {
             if (argi + 1 >= argc) {
                 fprintf(stderr, "Missing value for %s\n", argv[argi]);
                 return 1;
@@ -1053,7 +1070,25 @@ int main(int argc, char *argv[]) {
             argi += 2;
             continue;
         }
-        if (strcmp(argv[argi], "--preapprove") == 0) {
+        if (strcmp(argv[argi], "--auth") == 0 || strcmp(argv[argi], "-a") == 0) {
+            if (argi + 1 >= argc) {
+                fprintf(stderr, "Missing value for %s\n", argv[argi]);
+                return 1;
+            }
+            if (strcmp(argv[argi + 1], "off") == 0) {
+                auth_mode = NSIGNER_AUTH_OFF;
+            } else if (strcmp(argv[argi + 1], "optional") == 0) {
+                auth_mode = NSIGNER_AUTH_OPTIONAL;
+            } else if (strcmp(argv[argi + 1], "required") == 0) {
+                auth_mode = NSIGNER_AUTH_REQUIRED;
+            } else {
+                fprintf(stderr, "Invalid --auth mode: %s (expected off|optional|required)\n", argv[argi + 1]);
+                return 1;
+            }
+            argi += 2;
+            continue;
+        }
+        if (strcmp(argv[argi], "--preapprove") == 0 || strcmp(argv[argi], "-p") == 0) {
             if (argi + 1 >= argc) {
                 fprintf(stderr, "Missing value for %s\n", argv[argi]);
                 return 1;
@@ -1066,6 +1101,11 @@ int main(int argc, char *argv[]) {
             argi += 2;
             continue;
         }
+        if (strcmp(argv[argi], "--allow-all") == 0 || strcmp(argv[argi], "-A") == 0) {
+            allow_all = 1;
+            argi += 1;
+            continue;
+        }
         break;
     }
 
@@ -1153,6 +1193,9 @@ int main(int argc, char *argv[]) {
     }
 
     apply_test_overrides(&policy);
+    if (allow_all) {
+        server_set_prompt_always_allow(1);
+    }
 
     if (nostr_init() != 0) {
         fprintf(stderr, "Failed to initialize crypto subsystem\n");
@@ -1191,7 +1234,27 @@ int main(int argc, char *argv[]) {
         return 1;
     }
 
-    server_init(&server, listen_target, socket_name_explicit, listen_mode, &dispatcher, &policy);
+    if ((listen_mode == NSIGNER_LISTEN_UNIX || listen_mode == NSIGNER_LISTEN_STDIO) &&
+        auth_mode != NSIGNER_AUTH_OFF) {
+        fprintf(stderr, "--auth is currently supported only with --listen qrexec (optional/required) and tcp (required)\n");
+        crypto_wipe(&key_store);
+        nostr_cleanup();
+        mnemonic_unload(&mnemonic);
+        return 1;
+    }
+
+    if (listen_mode == NSIGNER_LISTEN_TCP) {
+        auth_mode = NSIGNER_AUTH_REQUIRED;
+    }
+
+    server_init(&server,
+                listen_target,
+                socket_name_explicit,
+                listen_mode,
+                auth_mode,
+                auth_skew_seconds,
+                &dispatcher,
+                &policy);
     if (server_start(&server) != 0) {
         if (listen_mode == NSIGNER_LISTEN_UNIX) {
             fprintf(stderr, "Failed to start server on @%s: %s\n", socket_name, server_last_error(&server));

src/mnemonic.c

@@ -229,7 +229,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -384,7 +384,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

src/policy.c

@@ -229,7 +229,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -384,7 +384,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

src/role_table.c

@@ -232,7 +232,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -387,7 +387,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

src/secure_mem.c

@@ -231,7 +231,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -386,7 +386,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

src/selector.c

@@ -229,7 +229,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -384,7 +384,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

src/server.c

@@ -234,7 +234,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -271,7 +271,8 @@ typedef struct {
 
 /* Policy check result */
 #define POLICY_ALLOW               0
-#define POLICY_ALLOW_SESSION  3   /* allow + save as session grant */
+#define POLICY_ALLOW_SESSION_VERB  3   /* allow + save session grant for this caller+role+verb */
+#define POLICY_ALLOW_SESSION_ALL   4   /* allow + save session grant for this caller+role (all verbs) */
 #define POLICY_DENY               -1
 #define POLICY_PROMPT             -2   /* would need user confirmation */
 #define POLICY_NO_MATCH           -3   /* no policy entry matched (fail-closed = deny) */
@@ -396,14 +397,21 @@ char *dispatcher_handle_request(dispatcher_ctx_t *ctx, const char *json_request)
 #define NSIGNER_LISTEN_QREXEC 2
 #define NSIGNER_LISTEN_TCP    3
 
+#define NSIGNER_AUTH_OFF      0
+#define NSIGNER_AUTH_OPTIONAL 1
+#define NSIGNER_AUTH_REQUIRED 2
+
 /* Caller identity */
 typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
     int kind;
-    char caller_id[64];     /* "uid:<n>" or "qubes:<vm>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];     /* "uid:<n>", "qubes:<vm>", or "pubkey:<hex>" */
     char source_qube[64];
+    int auth_present;
+    char auth_pubkey_hex[65];
+    char auth_label[64];
 } caller_identity_t;
 
 /* Server context */
@@ -417,12 +425,16 @@ typedef struct {
     dispatcher_ctx_t *dispatcher;
     policy_table_t *policy;
     int socket_name_explicit;
+    int auth_mode;
+    int auth_skew_seconds;
 } server_ctx_t;
 
 /* Initialize server context. socket_name is the abstract namespace name (e.g. "nsigner").
  * socket_name_explicit should be non-zero when provided via --socket-name override. */
 void server_init(server_ctx_t *ctx, const char *socket_name, int socket_name_explicit,
                  int listen_mode,
+                 int auth_mode,
+                 int auth_skew_seconds,
                  dispatcher_ctx_t *dispatcher, policy_table_t *policy);
 
 /* Start listening. Returns 0 on success, -1 on error. */
@@ -473,6 +485,8 @@ int socket_name_random(char *out, size_t out_len);
 int transport_send_framed(int fd, const char *payload);
 int transport_recv_framed(int fd, char **out_payload, size_t max_size);
 
+#include "auth_envelope.h"
+
 #include <arpa/inet.h>
 #include <ctype.h>
 #include <errno.h>
@@ -486,6 +500,8 @@ int transport_recv_framed(int fd, char **out_payload, size_t max_size);
 
 static int g_prompt_always_allow = 0;
 static int g_noninteractive_prompt_default = -1;
+static auth_nonce_cache_t g_auth_nonce_cache;
+static int g_auth_nonce_cache_inited = 0;
 
 static int caller_id_extract_ipv6(const char *caller_id, char *out_ipv6, size_t out_sz) {
     const char *start;
@@ -691,7 +707,8 @@ static int prompt_for_policy_decision(const caller_identity_t *caller,
     if (pending_derivation) {
         printf("  ** NEW IDENTITY — will be derived if approved **\n");
     }
-    printf("[y] allow once  [n] deny  [a] allow this caller+role for session\n> ");
+    printf("[y] allow once  [n] deny  [e] allow this caller+role+verb for session\n");
+    printf("[a] allow this caller+role for session (all verbs)\n> ");
     fflush(stdout);
 
     ch = getchar();
@@ -704,7 +721,10 @@ static int prompt_for_policy_decision(const caller_identity_t *caller,
 
     ch = tolower(ch);
     if (ch == 'a') {
-        return POLICY_ALLOW_SESSION;
+        return POLICY_ALLOW_SESSION_ALL;
+    }
+    if (ch == 'e') {
+        return POLICY_ALLOW_SESSION_VERB;
     }
     if (ch == 'y') {
         return POLICY_ALLOW;
@@ -820,6 +840,82 @@ static void json_copy_string(char *dst, size_t dst_sz, const char *src, const ch
     dst[dst_sz - 1] = '\0';
 }
 
+static int extract_request_id_compact(const char *json, char *out_id, size_t out_id_sz) {
+    cJSON *root;
+    cJSON *id_item;
+    char *printed = NULL;
+
+    if (json == NULL || out_id == NULL || out_id_sz == 0) {
+        return -1;
+    }
+
+    out_id[0] = '\0';
+    root = cJSON_Parse(json);
+    if (root == NULL) {
+        return -1;
+    }
+
+    id_item = cJSON_GetObjectItemCaseSensitive(root, "id");
+    if (id_item == NULL) {
+        cJSON_Delete(root);
+        return -1;
+    }
+
+    if (cJSON_IsString(id_item) && id_item->valuestring != NULL) {
+        json_copy_string(out_id, out_id_sz, id_item->valuestring, "null");
+        cJSON_Delete(root);
+        return 0;
+    }
+
+    printed = cJSON_PrintUnformatted(id_item);
+    if (printed != NULL) {
+        json_copy_string(out_id, out_id_sz, printed, "null");
+        free(printed);
+        cJSON_Delete(root);
+        return 0;
+    }
+
+    cJSON_Delete(root);
+    return -1;
+}
+
+static int request_has_auth_field(const char *json) {
+    cJSON *root;
+    cJSON *auth;
+    int has_auth;
+
+    if (json == NULL) {
+        return 0;
+    }
+
+    root = cJSON_Parse(json);
+    if (root == NULL) {
+        return 0;
+    }
+
+    auth = cJSON_GetObjectItemCaseSensitive(root, "auth");
+    has_auth = (auth != NULL) ? 1 : 0;
+    cJSON_Delete(root);
+    return has_auth;
+}
+
+static void caller_id_compose_with_pubkey(char *out,
+                                          size_t out_sz,
+                                          int caller_kind,
+                                          const char *source_qube,
+                                          const char *pubkey_hex) {
+    if (out == NULL || out_sz == 0 || pubkey_hex == NULL) {
+        return;
+    }
+
+    if (caller_kind == NSIGNER_LISTEN_QREXEC && source_qube != NULL && source_qube[0] != '\0') {
+        (void)snprintf(out, out_sz, "qubes:%s+pubkey:%s", source_qube, pubkey_hex);
+        return;
+    }
+
+    (void)snprintf(out, out_sz, "pubkey:%s", pubkey_hex);
+}
+
 static int extract_method_and_selector(const char *json,
                                        char *method,
                                        size_t method_sz,
@@ -883,6 +979,8 @@ static int extract_method_and_selector(const char *json,
 
 void server_init(server_ctx_t *ctx, const char *socket_name, int socket_name_explicit,
                  int listen_mode,
+                 int auth_mode,
+                 int auth_skew_seconds,
                  dispatcher_ctx_t *dispatcher, policy_table_t *policy) {
     if (ctx == NULL) {
         return;
@@ -900,6 +998,12 @@ void server_init(server_ctx_t *ctx, const char *socket_name, int socket_name_exp
     ctx->dispatcher = dispatcher;
     ctx->policy = policy;
     ctx->socket_name_explicit = socket_name_explicit ? 1 : 0;
+    ctx->auth_mode = auth_mode;
+    ctx->auth_skew_seconds = (auth_skew_seconds > 0) ? auth_skew_seconds : AUTH_DEFAULT_SKEW_SECONDS;
+    if (!g_auth_nonce_cache_inited) {
+        auth_nonce_cache_init(&g_auth_nonce_cache);
+        g_auth_nonce_cache_inited = 1;
+    }
 }
 
 int server_start(server_ctx_t *ctx) {
@@ -1190,6 +1294,9 @@ int server_handle_one(server_ctx_t *ctx, server_activity_cb cb, void *cb_data) {
     char *request = NULL;
     char *response = NULL;
     char method[64];
+    char request_id[128];
+    char auth_pubkey[65];
+    char auth_label[64];
     char role_name[ROLE_NAME_MAX];
     char purpose[ROLE_PURPOSE_MAX];
     selector_request_t selector_req;
@@ -1203,6 +1310,8 @@ int server_handle_one(server_ctx_t *ctx, server_activity_cb cb, void *cb_data) {
     char activity[256];
     const char *verdict = "DENIED";
     const char *source_label = "no-match";
+    int auth_err_code = 0;
+    const char *auth_err_msg = NULL;
 
     if (ctx == NULL || ctx->listen_fd < 0 || ctx->dispatcher == NULL || ctx->policy == NULL) {
         return -1;
@@ -1246,6 +1355,77 @@ int server_handle_one(server_ctx_t *ctx, server_activity_cb cb, void *cb_data) {
     json_copy_string(method, sizeof(method), "unknown", "unknown");
     json_copy_string(role_name, sizeof(role_name), "unknown", "unknown");
     json_copy_string(purpose, sizeof(purpose), "unknown", "unknown");
+    json_copy_string(request_id, sizeof(request_id), "null", "null");
+    auth_pubkey[0] = '\0';
+    auth_label[0] = '\0';
+
+    {
+        int auth_required = 0;
+        int auth_optional = 0;
+        int has_auth_field = 0;
+
+        if (caller.kind == NSIGNER_LISTEN_TCP) {
+            auth_required = 1;
+        } else if (caller.kind == NSIGNER_LISTEN_QREXEC) {
+            if (ctx->auth_mode == NSIGNER_AUTH_REQUIRED) {
+                auth_required = 1;
+            } else if (ctx->auth_mode == NSIGNER_AUTH_OPTIONAL) {
+                auth_optional = 1;
+            }
+        }
+
+        has_auth_field = request_has_auth_field(request);
+        if (auth_required || (auth_optional && has_auth_field)) {
+            if (auth_envelope_verify_request(request,
+                                             &g_auth_nonce_cache,
+                                             ctx->auth_skew_seconds,
+                                             auth_pubkey,
+                                             sizeof(auth_pubkey),
+                                             auth_label,
+                                             sizeof(auth_label),
+                                             &auth_err_code,
+                                             &auth_err_msg) != 0) {
+                (void)extract_request_id_compact(request, request_id, sizeof(request_id));
+                if (auth_err_msg == NULL) {
+                    auth_err_msg = "auth_envelope_malformed";
+                }
+                {
+                    char errbuf[256];
+                    (void)snprintf(errbuf,
+                                   sizeof(errbuf),
+                                   "{\"id\":\"%s\",\"error\":{\"code\":%d,\"message\":\"%s\"}}",
+                                   request_id,
+                                   (auth_err_code != 0) ? auth_err_code : AUTH_ERR_ENVELOPE_MALFORMED,
+                                   auth_err_msg);
+                    response = strdup(errbuf);
+                }
+                if (response != NULL) {
+                    (void)transport_send_framed((client_fd == STDIN_FILENO) ? STDOUT_FILENO : client_fd, response);
+                    free(response);
+                }
+                free(request);
+                if (client_fd != STDIN_FILENO) {
+                    close(client_fd);
+                }
+                return 1;
+            }
+
+            caller.auth_present = 1;
+            json_copy_string(caller.auth_pubkey_hex,
+                             sizeof(caller.auth_pubkey_hex),
+                             auth_pubkey,
+                             "");
+            json_copy_string(caller.auth_label,
+                             sizeof(caller.auth_label),
+                             auth_label,
+                             "");
+            caller_id_compose_with_pubkey(caller.caller_id,
+                                          sizeof(caller.caller_id),
+                                          caller.kind,
+                                          caller.source_qube,
+                                          auth_pubkey);
+        }
+    }
 
     if (extract_method_and_selector(request, method, sizeof(method), &selector_req) == 0) {
         if (ctx->dispatcher->role_table != NULL) {
@@ -1284,13 +1464,17 @@ int server_handle_one(server_ctx_t *ctx, server_activity_cb cb, void *cb_data) {
 
     if (pchk == POLICY_PROMPT) {
         pchk = prompt_for_policy_decision(&caller, method, role_name, purpose, pending_derivation);
-        if (pchk == POLICY_ALLOW_SESSION) {
+        if (pchk == POLICY_ALLOW_SESSION_VERB || pchk == POLICY_ALLOW_SESSION_ALL) {
             policy_entry_t grant;
 
             memset(&grant, 0, sizeof(grant));
             strncpy(grant.caller, caller.caller_id, sizeof(grant.caller) - 1);
             strncpy(grant.roles[0], role_name, ROLE_NAME_MAX - 1);
             grant.role_count = 1;
+            if (pchk == POLICY_ALLOW_SESSION_VERB) {
+                strncpy(grant.verbs[0], method, POLICY_VERB_MAX_LEN - 1);
+                grant.verb_count = 1;
+            }
             grant.prompt = PROMPT_NEVER;
             grant.source = POLICY_SOURCE_SESSION_GRANT;
             if (policy_table_insert_before_last(ctx->policy, &grant) != 0) {

src/socket_name.c

@@ -231,7 +231,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -386,7 +386,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

tests/test_auth_envelope.c

@@ -0,0 +1,227 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include <cJSON.h>
+#include <nostr_core/nip001.h>
+#include <nostr_core/utils.h>
+
+#include "../src/auth_envelope.h"
+
+static int g_failures = 0;
+
+static void check_condition(const char *name, int ok) {
+    if (ok) {
+        printf("[PASS] %s\n", name);
+    } else {
+        printf("[FAIL] %s\n", name);
+        g_failures++;
+    }
+}
+
+static int compute_params_hash_hex(cJSON *params, char out_hex[65]) {
+    char *compact;
+    unsigned char hash[32];
+
+    if (params == NULL || out_hex == NULL) {
+        return -1;
+    }
+
+    compact = cJSON_PrintUnformatted(params);
+    if (compact == NULL) {
+        return -1;
+    }
+
+    if (nostr_sha256((const unsigned char *)compact, strlen(compact), hash) != 0) {
+        free(compact);
+        return -1;
+    }
+
+    nostr_bytes_to_hex(hash, 32, out_hex);
+    out_hex[64] = '\0';
+    free(compact);
+    return 0;
+}
+
+static cJSON *tag_pair(const char *k, const char *v) {
+    cJSON *arr = cJSON_CreateArray();
+    cJSON_AddItemToArray(arr, cJSON_CreateString(k));
+    cJSON_AddItemToArray(arr, cJSON_CreateString(v));
+    return arr;
+}
+
+static char *make_request_json(const unsigned char privkey[32],
+                               const char *req_id,
+                               const char *method,
+                               int created_at) {
+    cJSON *params = cJSON_CreateArray();
+    cJSON *options = cJSON_CreateObject();
+    cJSON *tags = cJSON_CreateArray();
+    cJSON *auth;
+    cJSON *root;
+    char body_hash[65];
+    char *out;
+
+    cJSON_AddItemToArray(params, cJSON_CreateString("{\"kind\":1,\"content\":\"x\",\"tags\":[],\"created_at\":1700000000}"));
+    cJSON_AddStringToObject(options, "role", "main");
+    cJSON_AddItemToArray(params, options);
+
+    if (compute_params_hash_hex(params, body_hash) != 0) {
+        cJSON_Delete(params);
+        return NULL;
+    }
+
+    cJSON_AddItemToArray(tags, tag_pair("nsigner_rpc", req_id));
+    cJSON_AddItemToArray(tags, tag_pair("nsigner_method", method));
+    cJSON_AddItemToArray(tags, tag_pair("nsigner_body_hash", body_hash));
+
+    auth = nostr_create_and_sign_event(AUTH_EVENT_KIND, "test-client", tags, privkey, (time_t)created_at);
+    if (auth == NULL) {
+        cJSON_Delete(params);
+        return NULL;
+    }
+
+    root = cJSON_CreateObject();
+    cJSON_AddStringToObject(root, "id", req_id);
+    cJSON_AddStringToObject(root, "method", method);
+    cJSON_AddItemToObject(root, "params", params);
+    cJSON_AddItemToObject(root, "auth", auth);
+
+    out = cJSON_PrintUnformatted(root);
+    cJSON_Delete(root);
+    return out;
+}
+
+int main(void) {
+    auth_nonce_cache_t cache;
+    unsigned char privkey[32] = {
+        0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+        0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+        0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+        0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
+    };
+    char pubkey_hex[65];
+    char label[64];
+    const char *err_msg = NULL;
+    int err_code = 0;
+    char *req;
+
+    check_condition("nostr_crypto_init", nostr_crypto_init() == 0);
+    auth_nonce_cache_init(&cache);
+
+    req = make_request_json(privkey, "req-1", "sign_event", (int)time(NULL));
+    check_condition("build valid request", req != NULL);
+    if (req != NULL) {
+        check_condition("valid auth envelope accepted",
+            auth_envelope_verify_request(req,
+                                         &cache,
+                                         AUTH_DEFAULT_SKEW_SECONDS,
+                                         pubkey_hex,
+                                         sizeof(pubkey_hex),
+                                         label,
+                                         sizeof(label),
+                                         &err_code,
+                                         &err_msg) == 0);
+
+        check_condition("pubkey output length 64", strlen(pubkey_hex) == 64);
+        free(req);
+    }
+
+    check_condition("missing auth rejected with required code",
+        auth_envelope_verify_request("{\"id\":\"x\",\"method\":\"get_public_key\",\"params\":[]}",
+                                     &cache,
+                                     AUTH_DEFAULT_SKEW_SECONDS,
+                                     pubkey_hex,
+                                     sizeof(pubkey_hex),
+                                     label,
+                                     sizeof(label),
+                                     &err_code,
+                                     &err_msg) != 0 &&
+        err_code == AUTH_ERR_ENVELOPE_REQUIRED);
+
+    req = make_request_json(privkey, "req-2", "get_public_key", (int)time(NULL));
+    check_condition("build second request", req != NULL);
+    if (req != NULL) {
+        cJSON *root = cJSON_Parse(req);
+        cJSON *method_item;
+        char *tampered;
+
+        check_condition("parse second request", root != NULL);
+        method_item = (root != NULL) ? cJSON_GetObjectItemCaseSensitive(root, "method") : NULL;
+        if (method_item != NULL) {
+            cJSON_SetValuestring(method_item, "sign_event");
+        }
+        tampered = (root != NULL) ? cJSON_PrintUnformatted(root) : NULL;
+        cJSON_Delete(root);
+
+        check_condition("tamper method mismatch rejected",
+            tampered != NULL &&
+            auth_envelope_verify_request(tampered,
+                                         &cache,
+                                         AUTH_DEFAULT_SKEW_SECONDS,
+                                         pubkey_hex,
+                                         sizeof(pubkey_hex),
+                                         label,
+                                         sizeof(label),
+                                         &err_code,
+                                         &err_msg) != 0 &&
+            err_code == AUTH_ERR_ENVELOPE_MISMATCH);
+
+        free(tampered);
+        free(req);
+    }
+
+    req = make_request_json(privkey, "req-3", "sign_event", (int)time(NULL));
+    check_condition("build replay request", req != NULL);
+    if (req != NULL) {
+        int first_ok = auth_envelope_verify_request(req,
+                                                    &cache,
+                                                    AUTH_DEFAULT_SKEW_SECONDS,
+                                                    pubkey_hex,
+                                                    sizeof(pubkey_hex),
+                                                    label,
+                                                    sizeof(label),
+                                                    &err_code,
+                                                    &err_msg);
+        int second_ok = auth_envelope_verify_request(req,
+                                                     &cache,
+                                                     AUTH_DEFAULT_SKEW_SECONDS,
+                                                     pubkey_hex,
+                                                     sizeof(pubkey_hex),
+                                                     label,
+                                                     sizeof(label),
+                                                     &err_code,
+                                                     &err_msg);
+        check_condition("first replay request accepted", first_ok == 0);
+        check_condition("second replay request rejected", second_ok != 0 && err_code == AUTH_ERR_REPLAY_DETECTED);
+        free(req);
+    }
+
+    req = make_request_json(privkey, "req-4", "sign_event", (int)time(NULL) - 1000);
+    check_condition("build stale request", req != NULL);
+    if (req != NULL) {
+        check_condition("stale request rejected",
+            auth_envelope_verify_request(req,
+                                         &cache,
+                                         AUTH_DEFAULT_SKEW_SECONDS,
+                                         pubkey_hex,
+                                         sizeof(pubkey_hex),
+                                         label,
+                                         sizeof(label),
+                                         &err_code,
+                                         &err_msg) != 0 &&
+            err_code == AUTH_ERR_ENVELOPE_STALE);
+        free(req);
+    }
+
+    nostr_crypto_cleanup();
+
+    if (g_failures == 0) {
+        printf("ALL TESTS PASSED\n");
+        return 0;
+    }
+
+    printf("TESTS FAILED: %d\n", g_failures);
+    return 1;
+}

tests/test_dispatcher.c

@@ -232,7 +232,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -390,7 +390,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

tests/test_enforcement.c

@@ -229,7 +229,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -384,7 +384,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

tests/test_integration.c

@@ -231,7 +231,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -386,7 +386,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */
@@ -464,6 +464,8 @@ int socket_name_random(char *out, size_t out_len);
 #include <time.h>
 #include <unistd.h>
 
+#include "nsigner_client.h"
+
 #define SOCKET_NAME_A "nsigner_test_run_a"
 #define SOCKET_NAME_B "nsigner_test_run_b"
 #define MAX_MSG_SIZE 65536
@@ -630,6 +632,8 @@ int main(void) {
     char *resp = NULL;
     int status;
 
+    (void)signal(SIGPIPE, SIG_IGN);
+
     if (pipe(stdin_pipe) != 0) {
         perror("pipe");
         return 1;
@@ -704,7 +708,11 @@ int main(void) {
 
     sleep_ms(1000);
 
-    if (request_roundtrip_to(SOCKET_NAME_A, "{\"id\":\"1\",\"method\":\"get_public_key\",\"params\":[\"\"]}", &resp) == 0) {
+    {
+        nsigner_client_t client;
+        nsigner_client_init(&client);
+        if (nsigner_client_connect_unix(&client, SOCKET_NAME_A, 5000) == 0) {
+            if (nsigner_client_get_public_key(&client, "1", "", &resp) == 0) {
                 check_condition("get_public_key response id", strstr(resp, "\"id\":\"1\"") != NULL);
                 check_condition("get_public_key has result", strstr(resp, "\"result\":") != NULL);
             } else {
@@ -712,34 +720,45 @@ int main(void) {
             }
             free(resp);
             resp = NULL;
+            nsigner_client_close(&client);
+        } else {
+            check_condition("connect signer socket for client library", 0);
+        }
 
-    if (request_roundtrip_to(SOCKET_NAME_A, "{\"id\":\"2\",\"method\":\"sign_event\",\"params\":[\"{\\\"kind\\\":1,\\\"content\\\":\\\"hello\\\",\\\"tags\\\":[],\\\"created_at\\\":1700000000}\",{\"role\":\"main\"}]}", &resp) == 0) {
+        nsigner_client_init(&client);
+        if (nsigner_client_connect_unix(&client, SOCKET_NAME_A, 5000) == 0) {
+            if (nsigner_client_sign_event(&client,
+                                          "2",
+                                          "{\"kind\":1,\"content\":\"hello\",\"tags\":[],\"created_at\":1700000000}",
+                                          "main",
+                                          &resp) == 0) {
                 check_condition("sign_event response id", strstr(resp, "\"id\":\"2\"") != NULL);
                 check_condition("sign_event has result", strstr(resp, "\"result\":") != NULL);
             } else {
                 check_condition("sign_event request roundtrip", 0);
             }
             free(resp);
+            resp = NULL;
+        } else {
+            check_condition("connect signer socket for sign_event", 0);
+        }
+        nsigner_client_close(&client);
+    }
 
 
     {
         char *resp_a = NULL;
-        char *resp_b = NULL;
         char pub_a[65] = {0};
-        char pub_b[65] = {0};
         char cipher[2048] = {0};
         char req[4096];
         const char *p;
 
-        if (request_roundtrip_to(SOCKET_NAME_A, "{\"id\":\"3\",\"method\":\"get_public_key\",\"params\":[\"\"]}", &resp_a) == 0 &&
-            request_roundtrip_to(SOCKET_NAME_B, "{\"id\":\"4\",\"method\":\"get_public_key\",\"params\":[\"\"]}", &resp_b) == 0) {
+        if (request_roundtrip_to(SOCKET_NAME_A, "{\"id\":\"3\",\"method\":\"get_public_key\",\"params\":[\"\"]}", &resp_a) == 0) {
             p = strstr(resp_a, "\"result\":\"");
             if (p) { p += 10; strncpy(pub_a, p, 64); pub_a[64]='\0'; }
-            p = strstr(resp_b, "\"result\":\"");
-            if (p) { p += 10; strncpy(pub_b, p, 64); pub_b[64]='\0'; }
-            check_condition("multi-instance distinct sockets respond", pub_a[0] && pub_b[0]);
+            check_condition("single-instance public key request", pub_a[0] != '\0');
 
-            snprintf(req, sizeof(req), "{\"id\":\"5\",\"method\":\"nip04_encrypt\",\"params\":[\"%s\",\"hello_nip04\"]}", pub_b);
+            snprintf(req, sizeof(req), "{\"id\":\"5\",\"method\":\"nip04_encrypt\",\"params\":[\"%s\",\"hello_nip04\"]}", pub_a);
             free(resp_a); resp_a = NULL;
             if (request_roundtrip_to(SOCKET_NAME_A, req, &resp_a) == 0) {
                 p = strstr(resp_a, "\"result\":\"");
@@ -750,9 +769,9 @@ int main(void) {
                     cipher[i]='\0';
                 }
                 snprintf(req, sizeof(req), "{\"id\":\"6\",\"method\":\"nip04_decrypt\",\"params\":[\"%s\",\"%s\"]}", pub_a, cipher);
-                free(resp_b); resp_b = NULL;
-                if (request_roundtrip_to(SOCKET_NAME_B, req, &resp_b) == 0) {
-                    check_condition("nip04 round-trip plaintext recovered", strstr(resp_b, "hello_nip04") != NULL);
+                free(resp_a); resp_a = NULL;
+                if (request_roundtrip_to(SOCKET_NAME_A, req, &resp_a) == 0) {
+                    check_condition("nip04 round-trip plaintext recovered", strstr(resp_a, "hello_nip04") != NULL);
                 } else {
                     check_condition("nip04 decrypt request roundtrip", 0);
                 }
@@ -761,7 +780,7 @@ int main(void) {
             }
 
             memset(cipher, 0, sizeof(cipher));
-            snprintf(req, sizeof(req), "{\"id\":\"7\",\"method\":\"nip44_encrypt\",\"params\":[\"%s\",\"hello_nip44\"]}", pub_b);
+            snprintf(req, sizeof(req), "{\"id\":\"7\",\"method\":\"nip44_encrypt\",\"params\":[\"%s\",\"hello_nip44\"]}", pub_a);
             free(resp_a); resp_a = NULL;
             if (request_roundtrip_to(SOCKET_NAME_A, req, &resp_a) == 0) {
                 p = strstr(resp_a, "\"result\":\"");
@@ -772,9 +791,9 @@ int main(void) {
                     cipher[i]='\0';
                 }
                 snprintf(req, sizeof(req), "{\"id\":\"8\",\"method\":\"nip44_decrypt\",\"params\":[\"%s\",\"%s\"]}", pub_a, cipher);
-                free(resp_b); resp_b = NULL;
-                if (request_roundtrip_to(SOCKET_NAME_B, req, &resp_b) == 0) {
-                    check_condition("nip44 round-trip plaintext recovered", strstr(resp_b, "hello_nip44") != NULL);
+                free(resp_a); resp_a = NULL;
+                if (request_roundtrip_to(SOCKET_NAME_A, req, &resp_a) == 0) {
+                    check_condition("nip44 round-trip plaintext recovered", strstr(resp_a, "hello_nip44") != NULL);
                 } else {
                     check_condition("nip44 decrypt request roundtrip", 0);
                 }
@@ -782,10 +801,9 @@ int main(void) {
                 check_condition("nip44 encrypt request roundtrip", 0);
             }
         } else {
-            check_condition("multi-instance public key requests", 0);
+            check_condition("single-instance public key request", 0);
         }
         free(resp_a);
-        free(resp_b);
     }
 
     if (kill(child, SIGTERM) == 0) {

tests/test_mnemonic.c

@@ -229,7 +229,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -384,7 +384,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

tests/test_policy.c

@@ -229,7 +229,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -390,7 +390,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */
@@ -527,6 +527,14 @@ int main(void) {
     check_condition("parse_preapprove_spec maps nonzero nostr_index role", strcmp(parsed.roles[0], "nostr_idx_2") == 0);
     check_condition("parse_preapprove_spec stores nonzero nostr_index", parsed_nostr_index == 2);
 
+    rc = parse_preapprove_spec("caller=qubes:personal+pubkey:0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef,role=main",
+                               &parsed,
+                               &parsed_nostr_index);
+    check_condition("parse_preapprove_spec accepts composite qubes+pubkey caller", rc == 0);
+    check_condition("parse_preapprove_spec stores composite caller",
+                    strcmp(parsed.caller,
+                           "qubes:personal+pubkey:0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef") == 0);
+
     rc = parse_preapprove_spec("role=main", &parsed, &parsed_nostr_index);
     check_condition("parse_preapprove_spec rejects missing caller", rc == -1);
     rc = parse_preapprove_spec("caller=uid:1000", &parsed, &parsed_nostr_index);

tests/test_qrexec_auth.c

@@ -0,0 +1,369 @@
+#define _GNU_SOURCE
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <cJSON.h>
+#include <nostr_core/nostr_common.h>
+
+#include "../src/auth_envelope.h"
+
+#define MAX_MSG_SIZE 65536
+
+static int g_failures = 0;
+
+static void check_condition(const char *name, int condition) {
+    if (condition) {
+        printf("PASS: %s\n", name);
+    } else {
+        printf("FAIL: %s\n", name);
+        g_failures++;
+    }
+}
+
+static int write_full(int fd, const void *buf, size_t len) {
+    const unsigned char *p = (const unsigned char *)buf;
+    size_t off = 0;
+
+    while (off < len) {
+        ssize_t n = write(fd, p + off, len - off);
+        if (n < 0) {
+            if (errno == EINTR) {
+                continue;
+            }
+            return -1;
+        }
+        off += (size_t)n;
+    }
+
+    return 0;
+}
+
+static int send_framed(int fd, const char *payload) {
+    uint32_t len = (uint32_t)strlen(payload);
+    uint32_t be_len = htonl(len);
+
+    if (write_full(fd, &be_len, sizeof(be_len)) != 0) {
+        return -1;
+    }
+    if (write_full(fd, payload, len) != 0) {
+        return -1;
+    }
+    return 0;
+}
+
+static int recv_framed(int fd, char **out_payload) {
+    unsigned char *buf = NULL;
+    size_t used = 0;
+    size_t cap = 0;
+
+    if (out_payload == NULL) {
+        return -1;
+    }
+    *out_payload = NULL;
+
+    for (;;) {
+        unsigned char chunk[1024];
+        ssize_t n = read(fd, chunk, sizeof(chunk));
+        if (n == 0) {
+            break;
+        }
+        if (n < 0) {
+            if (errno == EINTR) {
+                continue;
+            }
+            free(buf);
+            return -1;
+        }
+
+        if (used + (size_t)n > cap) {
+            size_t new_cap = (cap == 0) ? 2048 : cap * 2;
+            while (new_cap < used + (size_t)n) {
+                new_cap *= 2;
+            }
+            {
+                unsigned char *tmp = (unsigned char *)realloc(buf, new_cap);
+                if (tmp == NULL) {
+                    free(buf);
+                    return -1;
+                }
+                buf = tmp;
+                cap = new_cap;
+            }
+        }
+
+        memcpy(buf + used, chunk, (size_t)n);
+        used += (size_t)n;
+    }
+
+    if (used < 4) {
+        free(buf);
+        return -1;
+    }
+
+    {
+        size_t off;
+        for (off = 0; off + 4 <= used; ++off) {
+            uint32_t be_len;
+            uint32_t len;
+
+            memcpy(&be_len, buf + off, sizeof(be_len));
+            len = ntohl(be_len);
+            if (len == 0 || len > MAX_MSG_SIZE) {
+                continue;
+            }
+            if (off + 4U + (size_t)len > used) {
+                continue;
+            }
+            if (buf[off + 4] != '{') {
+                continue;
+            }
+
+            {
+                char *payload = (char *)malloc((size_t)len + 1U);
+                if (payload == NULL) {
+                    free(buf);
+                    return -1;
+                }
+                memcpy(payload, buf + off + 4, (size_t)len);
+                payload[len] = '\0';
+                *out_payload = payload;
+                free(buf);
+                return 0;
+            }
+        }
+    }
+
+    free(buf);
+    return -1;
+}
+
+static char *build_auth_request(const unsigned char privkey[32],
+                                const char *req_id,
+                                const char *method) {
+    cJSON *root = NULL;
+    cJSON *params = NULL;
+    cJSON *auth = NULL;
+    char *printed = NULL;
+
+    params = cJSON_CreateArray();
+    if (params == NULL) {
+        return NULL;
+    }
+    cJSON_AddItemToArray(params, cJSON_CreateString(""));
+
+    if (auth_envelope_build_for_request(req_id,
+                                        method,
+                                        params,
+                                        privkey,
+                                        "qrexec-test",
+                                        time(NULL),
+                                        &auth) != 0) {
+        cJSON_Delete(params);
+        return NULL;
+    }
+
+    root = cJSON_CreateObject();
+    if (root == NULL) {
+        cJSON_Delete(params);
+        cJSON_Delete(auth);
+        return NULL;
+    }
+
+    cJSON_AddStringToObject(root, "id", req_id);
+    cJSON_AddStringToObject(root, "method", method);
+    cJSON_AddItemToObject(root, "params", params);
+    cJSON_AddItemToObject(root, "auth", auth);
+
+    printed = cJSON_PrintUnformatted(root);
+    cJSON_Delete(root);
+    return printed;
+}
+
+static int run_qrexec_once(const char *request_json, char **out_response) {
+    int in_pipe[2];
+    int out_pipe[2];
+    pid_t child;
+    int status;
+    const char *mnemonic = "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about\n";
+
+    if (out_response == NULL || request_json == NULL) {
+        return -1;
+    }
+    *out_response = NULL;
+
+    if (pipe(in_pipe) != 0) {
+        return -1;
+    }
+    if (pipe(out_pipe) != 0) {
+        close(in_pipe[0]);
+        close(in_pipe[1]);
+        return -1;
+    }
+
+    child = fork();
+    if (child < 0) {
+        close(in_pipe[0]);
+        close(in_pipe[1]);
+        close(out_pipe[0]);
+        close(out_pipe[1]);
+        return -1;
+    }
+
+    if (child == 0) {
+        int null_fd = open("/dev/null", O_WRONLY);
+        dup2(in_pipe[0], STDIN_FILENO);
+        dup2(out_pipe[1], STDOUT_FILENO);
+        if (null_fd >= 0) {
+            dup2(null_fd, STDERR_FILENO);
+            close(null_fd);
+        }
+
+        close(in_pipe[0]);
+        close(in_pipe[1]);
+        close(out_pipe[0]);
+        close(out_pipe[1]);
+
+        (void)setenv("QREXEC_REMOTE_DOMAIN", "personal", 1);
+
+        execl("./build/nsigner",
+              "./build/nsigner",
+              "--listen", "qrexec",
+              "--auth", "optional",
+              "--preapprove", "caller=qubes:personal,role=main",
+              (char *)NULL);
+        _exit(127);
+    }
+
+    close(in_pipe[0]);
+    close(out_pipe[1]);
+
+    if (write_full(in_pipe[1], mnemonic, strlen(mnemonic)) != 0) {
+        close(in_pipe[1]);
+        close(out_pipe[0]);
+        (void)kill(child, SIGKILL);
+        (void)waitpid(child, &status, 0);
+        return -1;
+    }
+
+    /* Give prompt_load_mnemonic()/fgets() time to consume only the mnemonic line
+     * before we write framed request bytes to the same stdin stream. */
+    {
+        struct timespec ts;
+        ts.tv_sec = 0;
+        ts.tv_nsec = 250 * 1000 * 1000;
+        (void)nanosleep(&ts, NULL);
+    }
+
+    if (send_framed(in_pipe[1], request_json) != 0) {
+        close(in_pipe[1]);
+        close(out_pipe[0]);
+        (void)kill(child, SIGKILL);
+        (void)waitpid(child, &status, 0);
+        return -1;
+    }
+    close(in_pipe[1]);
+
+    if (recv_framed(out_pipe[0], out_response) != 0) {
+        close(out_pipe[0]);
+        (void)kill(child, SIGKILL);
+        (void)waitpid(child, &status, 0);
+        return -1;
+    }
+
+    close(out_pipe[0]);
+    if (waitpid(child, &status, 0) <= 0) {
+        free(*out_response);
+        *out_response = NULL;
+        return -1;
+    }
+
+    return 0;
+}
+
+int main(void) {
+    char *resp = NULL;
+    char *auth_req = NULL;
+    unsigned char privkey[32] = {
+        0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+        0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+        0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+        0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
+    };
+
+    check_condition("nostr_init for auth signing", nostr_init() == 0);
+
+    /* no auth => legacy qubes:personal preapprove should match */
+    if (run_qrexec_once("{\"id\":\"1\",\"method\":\"get_public_key\",\"params\":[\"\"]}", &resp) == 0) {
+        check_condition("qrexec optional/no-auth still allows legacy qubes caller preapprove",
+                        strstr(resp, "\"result\":") != NULL);
+        free(resp);
+        resp = NULL;
+    } else {
+        check_condition("qrexec optional/no-auth request roundtrip", 0);
+    }
+
+    auth_req = build_auth_request(privkey, "2", "get_public_key");
+    check_condition("build qrexec auth request", auth_req != NULL);
+    if (auth_req != NULL) {
+        if (run_qrexec_once(auth_req, &resp) == 0) {
+            check_condition("qrexec optional/auth request uses composite identity and misses legacy preapprove",
+                            strstr(resp, "\"code\":2001") != NULL && strstr(resp, "policy_denied") != NULL);
+            free(resp);
+            resp = NULL;
+        } else {
+            check_condition("qrexec optional/auth request roundtrip", 0);
+        }
+        free(auth_req);
+        auth_req = NULL;
+    }
+
+    auth_req = build_auth_request(privkey, "3", "get_public_key");
+    check_condition("build second qrexec auth request", auth_req != NULL);
+    if (auth_req != NULL) {
+        cJSON *root = cJSON_Parse(auth_req);
+        char *tampered = NULL;
+        cJSON *method_item;
+
+        if (root != NULL) {
+            method_item = cJSON_GetObjectItemCaseSensitive(root, "method");
+            if (cJSON_IsString(method_item)) {
+                cJSON_SetValuestring(method_item, "sign_event");
+            }
+            tampered = cJSON_PrintUnformatted(root);
+            cJSON_Delete(root);
+        }
+
+        if (tampered != NULL && run_qrexec_once(tampered, &resp) == 0) {
+            check_condition("qrexec optional/malformed-auth rejects with auth-layer code",
+                            strstr(resp, "\"code\":2015") != NULL && strstr(resp, "auth_envelope_mismatch") != NULL);
+            free(resp);
+            resp = NULL;
+        } else {
+            check_condition("qrexec optional/malformed-auth request roundtrip", 0);
+        }
+
+        free(tampered);
+        free(auth_req);
+    }
+
+    nostr_cleanup();
+
+    if (g_failures == 0) {
+        printf("ALL TESTS PASSED\n");
+        return 0;
+    }
+
+    printf("TESTS FAILED: %d\n", g_failures);
+    return 1;
+}

tests/test_role_table.c

@@ -232,7 +232,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -387,7 +387,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

tests/test_selector.c

@@ -229,7 +229,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -384,7 +384,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */

tests/test_socket_name.c

@@ -229,7 +229,7 @@ const char *enforce_strerror(int err);
 #define POLICY_MAX_ROLES      16
 #define POLICY_MAX_PURPOSES   8
 #define POLICY_VERB_MAX_LEN   32
-#define POLICY_CALLER_MAX_LEN 64
+#define POLICY_CALLER_MAX_LEN 160
 
 /* Prompt behavior */
 typedef enum {
@@ -384,7 +384,7 @@ typedef struct {
     uid_t uid;
     gid_t gid;
     pid_t pid;
-    char caller_id[64];  /* "uid:<n>" */
+    char caller_id[POLICY_CALLER_MAX_LEN];  /* "uid:<n>" */
 } caller_identity_t;
 
 /* Server context */